The order came through the McDonald's drive-thru window in Harborcreek Township, Pennsylvania, around 11 a.m. on Tuesday: Chicken McNuggets and a side of fries.
When the driver of the white Fusion with Ohio tags reached the payment window, an employee recognized him from news reports and called police.
The driver was Steve Stephens, the suspect in the Easter Sunday slaying of mechanic Robert Godwin in Cleveland.
"[The employee] said, 'I think that's the guy. Can you double check I'm right?'" franchise owner Thomas DuCharme said.
"When I saw him I knew it was him. It fits the profile. He didn't look that different than the picture but his beard was trimmed down."
Authorities said Stephens killed Godwin and posted video of the killing on Facebook before fleeing the state, triggering a nationwide manhunt.
The McDonald's employee called police as Stephens proceeded down the drive-thru, DuCharme said. Two cars were in front of his, and police were on the way by the time Stephens reached the pickup window.
To buy time, DuCharme gave Stephens his nuggets and told him his fries would take an extra minute. But Stephens did not wait, he said. He took his nuggets and drove off.
"He didn't want to wait for the fries, which was fine," DuCharme said. "We were just trying to make sure [the employee] got in contact with the state police."
By the time he pulled out of the driveway and onto Buffalo Road, state police were behind him, DuCharme said.
During the chase a trooper rammed into his car. While the car was spinning out of control Stephens pulled a pistol and shot himself in the head, Pennsylvania State Police said.
CNN's Brynn Gingras and Sonia Moghe contributed to this report.