Man pleads guilty to murder 2021 Benton County killing

COLUMBIA, Mo. (KMIZ)

A Springfield, Missouri, man pleaded guilty on Nov. 4 to killing a man in 2021 in Benton County.

Jack Wagner, 71, pleaded guilty in Henry County to second-degree murder. He was previously charged with first-degree murder and armed criminal action. He is being held at the Benton County Jail. He will be sentenced at 1:30 p.m. Wednesday, Feb. 3. His case was moved to Henry County in November 2025.

Cody Garrett, 28, was reported missing on June 21, 2021. Benton County deputies found Garrett's vehicle and remains off the trails near a bike park outside Warsaw, Missouri. An autopsy showed he had died by homicide.

Kayley and Michael Birnbaum, both of Springfield, are also charged in the case with first-degree murder and armed criminal action.

Michael Birnbaum has a pretrial conference scheduled for 11 a.m. Wednesday, Jan. 6. A five-day jury trial is set to begin at 8:15 a.m. Monday, May 24, 2027.

Kayley Birnbaum has a pretrial conference scheduled for 11 a.m. Wednesday, Dec. 2. A four-day jury trial is scheduled to begin in her case at 8:30 a.m. April 12, 2027.