By Howard Packowitz

BLOOMINGTON – McLean County prosecutors agreed on Monday to drop first-degree murder charges against a Tazewell County man in return for his help in convicting a co-defendant who killed her mother two years ago near McLean.

Matthew Isbell, 24, of Marquette Heights, pleaded guilty to second-degree murder and was sentenced to 12-years in prison.

Co-defendant Christine Roush from Washington is serving 40-years in prison for strangling and stabbing her mother, Teresa Poehlman, 47, of East Peoria, at the Sugar Grove Nature Preserve in Funks Grove in July 2017.

Isbell drove the two women to Funks Grove, then helped cover up the killing.

The second-degree murder charge alleges Isbell unreasonably believed a third unidentified person would harm him or his family if he did not help Roush kill her mother.

Authorities said Roush killed her mother to stop her from revealing Roush was a prostitute, which could have caused her to lose custody of her own child.

First Assistant State’s Attorney Brad Rigdon says prosecutors are pleased with the outcome of the case because it acknowledges Isbell’s cooperation, which Rigdon said was essential to securing the first degree murder conviction against Roush.

Rigdon credited the convictions to the “excellent” work of McLean County Sheriff’s investigators and the prosecutors who handled the case, Assistant State’s Attorneys Ashley Scarborough, Aaron Fredrick, and David Spence.

Howard Packowitz can be reached at [email protected]