Pennsylvania State Police found the gun believed to be used in the murder of Robert Godwin Sr. inside Steve Stephens' car after the Facebook killer committed suicide Tuesday.
Authorities recovered a .45 glock handgun inside the car after it spun out during a police pursuit in Erie, according to CNN.
Investigators are still processing the rest of the car and conducting forensic tests for further clues, police told CNN.
The gun is being processed for ballistics.
Officials say there were no receipts in the vehicle, so there is no indication right now of where Stephens spent his time on the run.
Investigators in Cleveland are trying to piece together where Stephens' spent the hours between the murder on Sunday and when the manhunt ended on Tuesday.
"Our process is to backtrack," said Cleveland Police Chief Calvin Williams.
"It will be helpful to figure out where he was," said FBI Special Agent Vicki Anderson. She added the information could be helpful in future cases.
Stephens' autopsy was scheduled for Wednesday morning.