Law enforcementCalumet County Sheriff's Department

Mark Wiegert

Calumet County investigator involved in the missing-person investigation and Brendan Dassey's interviews.

1,183 lines·78 proceedings·64 mentions·2 trials

About

Calumet County investigator Mark Wiegert testified about investigative work in the trials of Steven Avery and Brendan Dassey. In Avery’s trial, he described the early missing-person inquiry, searches of Avery’s property, and his later retrieval and transfer of a blood vial from a court file. He also relayed Lisa Buchner’s reported sighting of a woman photographing a van, while acknowledging that she could not identify the photographer or fix the day. In Dassey’s trial, Wiegert relayed Kayla Avery's report that Dassey told her he had seen Halbach pinned up in Avery's bedroom, heard screaming, and seen body parts in a fire. He described the February 27 and videotaped March 1 interviews of Dassey, including the point at which investigators began treating him as a suspect. He acknowledged intentionally false suggestions during questioning. Cross-examination tested those tactics and whether physical evidence supported details of Dassey’s account; Wiegert cited several items he believed were corroborative, while acknowledging limits including the absence of Dassey’s DNA profile or fingerprints and the lack of an identified Teresa Halbach hair among those recovered.

Trial Record (78)

AverySteven AveryFeb 12, 2007 – Mar 18, 2007Called by prosecution and defense

Mark Wiegert, a Calumet County investigator, testified in Steven Avery's 2007 trial about the missing-person investigation, his handling of a blood vial, and the limits of Lisa Buchner's reported photographer sighting.

Day 2

Feb 13, 2007

CrossDawn Pliszka — CrossDawn PliszkaJerome F. ButingMentioned

Summary

Buting tested the Auto Trader records and Pliszka's knowledge of private photo shoots; she could not establish whether Halbach made another such stop on October 31.

Mentioned in this proceeding.

DirectPamela Sturm — DirectPamela SturmKenneth R. KratzMentioned33lines spoken

Summary

Pamela Sturm described finding a branch-covered RAV4 during a volunteer search at Avery Salvage Yard; the court admitted vehicle photographs and her recorded call to investigators.

Mentioned in this proceeding.

CrossPamela Sturm — CrossPamela SturmJerome F. ButingMentioned

Summary

Buting tested Sturm's RAV4 observations and a later phone discovery; afterward, the court ordered a check for phone-incident reports and the parties addressed the date of Exhibit 25.

Mentioned in this proceeding.

Day 4

Feb 15, 2007

DirectBrett Bowe — DirectBrett BoweKenneth R. KratzMentioned

Summary

Brett Bowe described security and large-scale searches at and around the Avery property; the court admitted property photographs numbered 79 through 86.

Mentioned in this proceeding.

CrossBrett Bowe — CrossBrett BoweDean A. StrangMentioned

Summary

Strang tested Bowe's knowledge of search assignments and March entry logs; the court reserved ruling on admission of the five-page garage log.

Mentioned in this proceeding.

RedirectBrett Bowe — RedirectBrett BoweKenneth R. KratzMentioned

Summary

Bowe clarified nighttime lighting, the limits of a citizen group's search, and differences in searchers' evidence training.

Mentioned in this proceeding.

DirectPeter O'Connor — DirectPeter O'ConnorKenneth R. KratzMentioned

Summary

Peter O'Connor described the first roadside roadblock at Avery Road, vehicles leaving the property, and the limits of his search involvement.

Mentioned in this proceeding.

Day 5

Feb 16, 2007

DirectThomas Fassbender — DirectThomas FassbenderKenneth R. Kratz1highlightMentioned

Summary

Fassbender outlined the November 5–12 searches, RAV4 handling, and discoveries of a Toyota key, license plates, and bone pieces; a discovery dispute was also raised.

Mentioned in this proceeding.

Highlights (1)

testimony highlightFassbender identifies himself and Mark Wiegert as the two lead investigators and describes briefings and group decisions that directed the investigation.Open in transcript →

CrossThomas Fassbender — CrossThomas FassbenderJerome F. ButingMentioned

Summary

Buting challenged Fassbender on search-team choices, repeated searches, scene logs, and an anonymous smelter lead; Fassbender acknowledged limits in the trailer and garage evidence.

Mentioned in this proceeding.

Day 6

Feb 19, 2007

DirectJohn Ertl — DirectJohn ErtlThomas J. FallonMentioned

Summary

John Ertl traced crime-lab work on the RAV4, burn areas, and nearby search sites, and explained the limits of the garage's luminol result.

Mentioned in this proceeding.

CrossJohn Ertl — CrossJohn ErtlJerome F. ButingMentioned

Summary

Ertl was pressed on contamination, RAV4 timing, limited scene photography, negative garage-floor blood screening, and how burn pit material was collected.

Mentioned in this proceeding.

RedirectJohn Ertl — RedirectJohn ErtlThomas J. FallonMentioned

Summary

Ertl addressed SUV transport, hypothetical key DNA and blood cleanup, and the limits of his bloodstain expertise.

Mentioned in this proceeding.

DirectWilliam Tyson — DirectWilliam TysonKenneth R. KratzMentioned2lines spoken

Summary

Tyson traced RAV4 security, Calumet's oversight of the first residence search, seized items, and later hood-latch and DNA-related collection.

Mentioned in this proceeding.

Day 7

Feb 20, 2007

CrossWilliam Tyson — CrossWilliam TysonJerome F. ButingMentioned

Summary

Tyson qualified how closely he observed Manitowoc officers, distinguished the searches from the later key discovery, and described limited negative blood-testing results.

Mentioned in this proceeding.

DirectAndrew L. Colborn — DirectAndrew L. ColbornKenneth R. KratzMentioned

Summary

Colborn traced his Avery-property searches, described how a Toyota-emblem key was found and handled, and denied planting evidence.

Mentioned in this proceeding.

CrossAndrew L. Colborn — CrossAndrew L. ColbornDean A. StrangMentioned

Summary

Strang tested Colborn's reporting and recollection, played his apparent license-plate call, and questioned the omission of the Toyota key from his report.

Mentioned in this proceeding.

DirectJames Lenk — DirectJames LenkKenneth R. KratzMentioned

Summary

Lenk described Manitowoc's assisting role, qualified the scope of early property searches, and denied planting evidence or resentment over Avery's lawsuit.

Mentioned in this proceeding.

Day 8

Feb 21, 2007

DirectJames Lenk — DirectJames LenkKenneth R. KratzMentioned

Summary

Lenk described finding the bedroom key after the cabinet was moved, the officers' belief about its source, and his denial that he planted evidence.

Mentioned in this proceeding.

CrossJames Lenk — Cross resumesJames LenkDean A. StrangMentioned

Summary

Strang challenged Lenk's arrival time, the bedroom key's discovery, search documentation, and his failure to disclose a recent deposition in Avery's lawsuit.

Mentioned in this proceeding.

RecrossJames Lenk — RecrossJames LenkDean A. StrangMentioned

Summary

Lenk addressed a possible use for the scanner, qualified his knowledge of the license-plate call, and confirmed his transmittal-form role; Exhibit 214 was admitted.

Mentioned in this proceeding.

DirectDave Remiker — DirectDave RemikerKenneth R. KratzMentioned

Summary

Remiker described identifying Halbach's RAV4, assisting with property searches, recording an answering-machine message, and collecting a garage bullet fragment.

Mentioned in this proceeding.

CrossDave Remiker — CrossDave RemikerDean A. StrangMentioned

Summary

Strang tested Remiker's early focus on Avery through dispatch calls and questioned the warrant, residence searches, and gap between garage shell casings and the later bullet-fragment discovery.

Mentioned in this proceeding.

DirectDaniel Kucharski — DirectDaniel KucharskiKenneth R. KratzMentioned

Summary

Kucharski described the salvage-yard dog search and the next day's garage search, including .22 shell casings, evidence collection, and photographs of electrical cords.

Mentioned in this proceeding.

Day 9

Feb 22, 2007

CrossGary Steier — CrossGary SteierJerome F. ButingMentioned

Summary

Buting tested Manitowoc's return to the March search, Lenk's presence in search logs, and the limits of Steier's knowledge and vigilance.

Mentioned in this proceeding.

DirectKevin Heimerl — DirectKevin HeimerlKenneth R. KratzMentioned4lines spoken

Summary

Heimerl described burn-pit debris sorting, a marked clothing rivet, and his discovery of two bullets during the March garage search.

Mentioned in this proceeding.

Day 10

Feb 23, 2007

ProceduralRenewed search-suppression motion hearingMentioned

Summary

The defense renewed its challenge to searches of Avery's property; the State opposed suppression, and the court deferred a decision pending further burn-pit evidence.

Mentioned in this proceeding.

DirectSherry Culhane — DirectSherry CulhaneNorman A. Gahn3lines spoken

Summary

Culhane attributed RAV4 cargo-area and bullet-fragment DNA to Teresa Halbach, and several vehicle bloodstains to Steven Avery; the hood-latch and key profiles were consistent with Avery's. She qualified the partial remains profile and disclosed her own DNA in a bullet-test negative control, not in the bullet sample.

ProceduralEnd-of-day jury admonition after Culhane’s direct examinationMentioned

Summary

The court gave jurors weekend instructions, then admitted forensic exhibits and reviewed outstanding exhibit status. The defense reserved its position on whether five Crime Lab reports should go to the jury during deliberations.

Mentioned in this proceeding.

Day 13

Feb 28, 2007

DirectThomas Sturdivant — DirectThomas SturdivantThomas J. FallonMentioned

Summary

Sturdivant described finding apparent bone fragments near the burn pit, sifting debris with Crime Lab personnel, and preserving the scene; exhibits 363–371 and 373 were admitted.

Mentioned in this proceeding.

Day 14

Mar 1, 2007

DirectCurtis Thomas — DirectCurtis ThomasKenneth R. KratzMentioned

Summary

FBI engineer Curtis Thomas identified burned phone, camera, and PDA components and explained why he could not recover data from the damaged materials.

Mentioned in this proceeding.

DirectWilliam Newhouse — DirectWilliam NewhouseThomas J. FallonMentioned

Summary

Newhouse linked 11 submitted casings and bullet FL to the rifle, but could not identify the particular gun that fired bullet FK.

Mentioned in this proceeding.

Day 17

Mar 6, 2007

CrossLynn Zigmunt — CrossLynn ZigmuntJerome F. ButingMentioned

Summary

Zigmunt described gaps in file sign-in practices and supervision, then reviewed a video of the blood-vial box examination; the court limited her interpretation of its seals.

Mentioned in this proceeding.

RecrossLynn Zigmunt — RecrossLynn ZigmuntJerome F. ButingMentioned

Summary

Zigmunt distinguished the file's usual storage location from a viewing-area photograph; the court sustained a scope objection, then admitted Exhibits 468–471 after a witness-order discussion.

Mentioned in this proceeding.

Day 18

Mar 7, 2007

DirectRodney Pevytoe — DirectRodney PevytoeThomas J. FallonMentioned

Summary

Pevytoe described burn pit recoveries, comparisons with barrel contents, and examinations of other possible burn sites.

Mentioned in this proceeding.

CrossMichael Daniel Halbach — CrossMichael Daniel HalbachJerome F. ButingMentioned

Summary

Halbach said he did not believe he erased voicemail messages; the parties then recorded agreements about telephone testimony and witness order.

Mentioned in this proceeding.

DirectMark Wiegert — DirectMark WiegertKenneth R. Kratz45lines spoken

Summary

Wiegert described the blood-vial inquiry and FBI transfer; the court limited secondhand testimony and barred an access question.

CrossMark Wiegert — CrossMark WiegertDean A. Strang298lines spoken

Summary

Wiegert addressed investigative leads, two Avery-property searches, and the blood vial; the State then announced it was resting subject to exhibit matters.

Day 19

Mar 8, 2007

ProceduralRenewed challenge to November 5 warrant searchesMentioned

Summary

The defense and State argued over repeated searches under the November 5 warrant, particularly the burn area. The court made no new ruling.

Mentioned in this proceeding.

ProceduralAfternoon exhibit reconciliationMentioned

Summary

The court admitted several exhibits, and the State withdrew two disputed phone-record summaries before the defense case began.

Mentioned in this proceeding.

CrossLisa Buchner — CrossLisa BuchnerNorman A. GahnMentioned

Summary

Buchner could not date her sighting to the week of October 31, but mapped where she recalled seeing a woman and vehicles near her bus drop-off.

Mentioned in this proceeding.

ProceduralHearing on proposed Kakatsch testimonyMentioned

Summary

After a defense offer of proof, the court excluded proposed testimony from Ms. Kakatsch as minimally probative and potentially confusing.

Mentioned in this proceeding.

Day 20

Mar 9, 2007

DirectMark Wiegert — DirectMark WiegertDean A. Strang1highlight10lines spoken

Summary

Wiegert said Buchner's initial report placed a photographer sighting within a three-day window, without a recalled van color or weather.

Highlights (1)

testimony highlightWiegert confirmed that Buchner had placed her reported sighting on one of three days—October 31, November 1, or November 2—and said she could not recall the weather or the van's color.Open in transcript →

CrossMark Wiegert — CrossMark WiegertKenneth R. Kratz10lines spoken

Summary

Wiegert described Buchner's reported photographer sighting near an intersection and identified two vehicles there that Halbach had photographed; the court struck part of a speculative answer.

RedirectMark Wiegert — RedirectMark WiegertDean A. Strang1highlight8lines spoken

Summary

Wiegert said Ms Buchner could not identify the photographer or fix the day of her sighting, and he knew of no other female photographer in the area during the specified dates.

Highlights (1)

testimony highlightWiegert confirmed that the maroon van was not near the shop area, but cautioned that Ms Buchner had not identified the woman she saw or fixed the day of the sighting.Open in transcript →

RecrossMark Wiegert — RecrossMark WiegertKenneth R. Kratz1line spoken

Summary

Wiegert addressed uncertainty in Ms Buchner's sighting timeline; the court warned jurors about outside information and admitted Exhibit 501.

Day 21

Mar 12, 2007

ProceduralRulings on fair testing, search suppression, and charge dismissalMentioned

Summary

The court denied renewed fair-testing and search-suppression motions, but dismissed the false-imprisonment charge for insufficient evidence.

Mentioned in this proceeding.

Day 22

Mar 13, 2007

Charge ConferenceFormal Jury Instruction ConferenceMentioned

Summary

The court approved a defense-theory instruction, denied separate exhibit-weight and spoliation instructions, and agreed to add prior-statement language to the jury instructions.

Mentioned in this proceeding.

Day 23

Mar 14, 2007

ClosingState’s Closing Argument by Kenneth KratzKenneth R. KratzMentioned

Summary

Kratz began the State's closing with the RAV4, blood and DNA evidence, and burned electronics; an objection led the court to remind jurors that argument is not fact.

Mentioned in this proceeding.

Day 24

Mar 15, 2007

ClosingDefense closing argument by Dean StrangDean A. StrangMentioned

Summary

Strang urged jurors to find reasonable doubt, challenging the State's timeline, investigative conduct, forensic testing, and interpretation of physical evidence.

Mentioned in this proceeding.

DasseyBrendan DasseyApr 16, 2007 – Apr 25, 2007Called by prosecution

Mark Wiegert testified for the prosecution in Brendan Dassey's 2007 trial about Dassey's interviews and the investigation that followed them. Cross-examination focused on false suggestions during questioning and whether physical evidence corroborated Dassey's statements.

Day 1

Apr 16, 2007

OpeningState's Opening StatementKenneth R. KratzMentioned

Summary

Kratz outlined the State's theory that Dassey helped Avery assault and kill Halbach, then previewed Dassey's recorded statement and evidence the State said would corroborate it.

Mentioned in this proceeding.

OpeningDefense Opening StatementMark R. FremgenMentioned

Summary

Fremgen previewed an alternative account of Dassey's Halloween evening and challenged the expected physical evidence and reliability of his recorded statements.

Mentioned in this proceeding.

DirectKaren Halbach — DirectKaren HalbachKenneth R. KratzMentioned

Summary

Karen Halbach described Teresa's life, her last family visit, the search after she went missing, and exhibits the court received.

Mentioned in this proceeding.

DirectKatie Halbach — DirectKatie HalbachKenneth R. KratzMentioned

Summary

Katie Halbach identified a lanyard she gave Teresa, described jeans she selected as similar to Teresa's, and said she had not seen or heard from her sister after October 30.

Mentioned in this proceeding.

DirectThomas Fassbender — DirectThomas FassbenderKenneth R. KratzMentioned

Summary

Fassbender described the Avery Yard search, RAV4 handling, recovered items, and Dassey's reported February 27 account of garage-floor cleanup; the court limited two exhibit admissions.

Mentioned in this proceeding.

CrossThomas Fassbender — CrossThomas FassbenderRaymond L. EdelsteinMentioned

Summary

Edelstein challenged the physical links to Dassey and elicited Fassbender's acknowledgment that he first suggested blood in the garage-floor interview.

Mentioned in this proceeding.

Day 2

Apr 17, 2007

DirectWilliam Tyson — DirectWilliam TysonKenneth R. KratzMentioned

Summary

William Tyson described searches of Steven Avery's trailer, identified recovered items, and explained how he swabbed the hood latch of Teresa Halbach's vehicle.

Mentioned in this proceeding.

CrossWilliam Tyson — CrossWilliam TysonMark R. FremgenMentioned

Summary

Tyson was questioned about glove changes, items left or collected during trailer searches, bleach-bottle testing, and the limits of his RAV4 hood-latch swab.

Mentioned in this proceeding.

DirectKevin Heimerl — DirectKevin HeimerlKenneth R. KratzMentioned

Summary

Kevin Heimerl described a burn barrel, the sorting of burned debris, and a garage search that located two bullet items.

Mentioned in this proceeding.

DirectJohn Ertl — DirectJohn ErtlThomas J. FallonMentioned

Summary

Ertl described the RAV4's recovery, burned debris from a barrel and the burn pit, and the limits of garage luminol testing.

Mentioned in this proceeding.

DirectWilliam Newhouse — DirectWilliam NewhouseThomas J. FallonMentioned

Summary

Newhouse attributed 11 cartridge casings and one bullet to a Marlin rifle but could not identify that rifle as the source of a second, damaged bullet.

Mentioned in this proceeding.

DirectKenneth Olson — DirectKenneth OlsonThomas J. FallonMentioned

Summary

Olson reported lead near defects in two charred cranial fragments, said a bullet could be its source, and described the limits of his burned-electronics examination.

Mentioned in this proceeding.

Day 3

Apr 18, 2007

DirectKayla Avery — DirectKayla AveryThomas J. FallonMentioned

Summary

Kayla Avery disavowed earlier reports about what Brendan told her concerning a fire and Teresa Halbach, saying she had made up the account.

Mentioned in this proceeding.

Day 4

Apr 19, 2007

DirectRodney Pevytoe — DirectRodney PevytoeThomas J. FallonMentioned

Summary

Rodney Pevytoe described suspected remains recovered from burn-pit debris, bone material he identified within tire wire, and his qualified opinions about the fire's fuel and duration.

Mentioned in this proceeding.

DirectMark Wiegert — DirectMark WiegertThomas J. Fallon40lines spoken

Summary

Wiegert said Kayla Avery reported that Brendan Dassey told her he had seen Teresa Halbach pinned up in Steven Avery's bedroom, heard screaming, and seen body parts in a fire. He described how Kayla's earlier interview led investigators to question Brendan again and identified her March 7 written statement.

Day 5

Apr 20, 2007

DirectMark Wiegert — DirectMark WiegertThomas J. Fallon99lines spoken

Summary

Wiegert explained the February 27 and March 1 interviews, acknowledged deceptive questioning techniques, and discussed Dassey's drawings after the jury viewed the interview DVD.

CrossMark Wiegert — CrossMark WiegertRaymond L. Edelstein3highlights85lines spoken

Summary

Edelstein tested differences between Kayla Avery's account, Brendan Dassey's interview, and two bedroom exhibits, then questioned Wiegert about when Brendan became a suspect.

Highlights (3)

confrontationEdelstein established that Kayla Avery's March account came six days after the March 1 press conference. Wiegert agreed that Brendan did not describe Teresa as pinned in a chair in the interview video, but said the chair detail differed while the account of her being pinned did not.Open in transcript →

testimony highlightComparing Exhibits 208 and 211, Wiegert said the computer-generated depiction drew on both Brendan Dassey's and Jodi Stachowski's statements and acknowledged differences between the two exhibits.Open in transcript →

testimony highlightWiegert said he considered Brendan Dassey a suspect on March 1, the day Wiegert said Brendan told investigators he had killed, raped, and mutilated Teresa Halbach.Open in transcript →

CrossMark Wiegert — Cross-examination resumesMark WiegertRaymond L. Edelstein202lines spoken

Summary

Edelstein tested Wiegert's interview tactics, gaps in the February 27 transcript, and the scientific link between listed physical items and Brendan Dassey.

Day 6

Apr 21, 2007

CrossMark Wiegert — CrossMark WiegertRaymond L. Edelstein287lines spoken

Summary

Edelstein tested Wiegert's March 1 interview techniques and the physical corroboration for Brendan's account; Wiegert acknowledged false suggestions and explained why recovered hair was not compared.

RedirectMark Wiegert — RedirectMark WiegertThomas J. Fallon1highlight15lines spoken

Summary

On redirect, Wiegert explained his views on missing blood spatter and cited physical findings he believed corroborated Brendan's interview account despite the absence of Brendan's DNA profile or fingerprints.

Highlights (1)

testimony highlightAsked about the absence of blood spatter in the SUV, Wiegert explained why he would not expect substantial spatter from the stabbing described, while characterizing his medical knowledge as limited.Open in transcript →

RecrossMark Wiegert — RecrossMark WiegertRaymond L. Edelstein33lines spoken

Summary

Edelstein tested Wiegert's corroboration claims against possible prior knowledge, limits of the bleach-bottle evidence, and investigators' existing knowledge of one gunshot wound.

Day 7

Apr 23, 2007

DirectBrendan Dassey — DirectBrendan DasseyMark R. FremgenMentioned

Summary

Brendan Dassey described his October 31 activities, the bonfire and garage cleanup, and his response to statements he made to investigators.

Mentioned in this proceeding.

CrossBrendan Dassey — CrossBrendan DasseyThomas J. FallonMentioned

Summary

Fallon tested Dassey's trial denials against recorded statements, his bonfire and garage-cleanup account, and drawings he made for investigators.

Mentioned in this proceeding.

ProceduralRenewed motion to exclude Dr. Gordon, ruling, and separate proposed State rebuttal witnessesMentioned

Summary

The court denied the renewed motion to exclude Dr. Gordon, clarified the limits of his testimony, and deferred a decision on Mr. Buckley's proposed rebuttal.

Mentioned in this proceeding.

Day 8

Apr 24, 2007

DirectRobert H. Gordon — DirectRobert H. GordonMark R. FremgenMentioned

Summary

Robert H. Gordon testified that his testing and review of interview materials led him to conclude Brendan Dassey was highly suggestible when questioned with leading questions or mild pressure. The examination also addressed disputed IQ-chart labeling and records Gordon reviewed after writing his report.

Mentioned in this proceeding.

Day 9

Apr 25, 2007

ProceduralRenewed motion to dismiss Count 3 and corroboration rulingMentioned

Summary

The court denied the renewed motion to dismiss amended Count 3, finding sufficient corroboration of Brendan Dassey's confession.

Mentioned in this proceeding.

ClosingDefense closing argument by Mark R. FremgenMark R. FremgenMentioned

Summary

Fremgen argued that forensic gaps and changing details in Dassey's statements left reasonable doubt.

Mentioned in this proceeding.

ClosingDefense closing argument by Raymond L. EdelsteinRaymond L. EdelsteinMentioned

Summary

Edelstein challenged the reliability and corroboration of Dassey's statements and urged not-guilty verdicts on all counts.

Mentioned in this proceeding.

RebuttalProsecution rebuttal closing argument by Thomas J. FallonThomas J. FallonMentioned

Summary

Fallon rebutted challenges to Dassey's statements and the forensic gaps, played part of the March 1 interview, and requested guilty verdicts.

Mentioned in this proceeding.