Uden said he picked up the three on Sept. 13, 1980, and drove to an area in Fremont County, according to the AP. All four got out of the car and he shot his ex-wife, then both boys, before allegedly concealing the bodies.
It is unclear if the bodies of Virginia Uden and her children were ever found.
Deputy Fremont County Attorney Patrick LeBrun, who is prosecuting, declined to comment on the details of the case to ABC News. It is not known if Uden has an attorney.
Gerald and Alice Uden have been living in Christian County, Missouri, for approximately 22 years, the Christian County Sheriff's Department said.
According to Missouri court records, Alice Uden has a daughter, Erica Hayes. It is unclear if Gerald Uden is her father.
ABC News' attempts to reach Hayes were not immediately successful.