John Christofferson
Lead investigator, then a Wisconsin Department of Justice special agent assisting the La Crosse County Sheriff's Department
John Christofferson (Lead investigator, then a Wisconsin Department of Justice special agent assisting the La Crosse County Sheriff's Department) has appeared as a guest on 1 episode in TMT. Topics they speak about most include Murders of Dennis and Merna Koula, Surveillance video evidence, Computer forensics.
In their words
Positions and remarks grouped by topic, each with the exact quote and where it was said.
Murders of Dennis and Merna Koula
Christofferson argued that Eric never asked for help for his parents during the 911 call.
“once you take the time to listen to the 911 call, you realize that Eric never asks for help”
48 Hours: Desperate Measures (May 14, 2026) · Listen from 17:45
Christofferson noted that the dresser drawers were searched bottom-up, which he said is not how real burglars behave.
“they're indicating that they go to the bottom drawer first, pull it out, shuffle through it, then pull out the next drawer, and so forth, going up”
48 Hours: Desperate Measures (May 14, 2026) · Listen from 9:12
Christofferson believed the killer was lying in wait, prepared to execute the couple.
“This was somebody that was lying in wait for them, prepared to execute them”
48 Hours: Desperate Measures (May 14, 2026) · Listen from 2:24
Surveillance video evidence
Christofferson said Eric's absence from the Shopko surveillance footage opened a window in which he could have killed his parents.
“it now opens up that period of his timeline where he has the opportunity to get to his parents' house and kill them”
48 Hours: Desperate Measures (May 14, 2026) · Listen from 23:32
Computer forensics
Christofferson said a forensic computer expert found Merna's last keystroke was at 5:41 p.m. on May 21.
“her last keystroke on that computer was at 5.41 p.m. on May 21st”
48 Hours: Desperate Measures (May 14, 2026) · Listen from 12:02
Appearances
Desperate Measures48 Hours · May 14, 2026 · 41 min
Peter Van Sant reports on the 2010 shooting deaths of Dennis and Merna Koula in Wisconsin and the circumstantial murder case against their son Eric.
Often appears with
- Peter Van Sant · 1 shared episode
- Eric Koula · 1 shared episode
- Cindy Kowal · 1 shared episode
- Christine Koula · 1 shared episode
- Tim Gruenke · 1 shared episode
- Jim Koby · 1 shared episode
- Helen Van Roo · 1 shared episode
- Dexter Koula · 1 shared episode