New video shows missing postal worker Kierra Coles before she vanished in 2018

CHICAGO (CBS) -- Chicago police have released new video of missing postal worker Kierra Coles, who was last seen nearly four years ago.

The footage shows Coles, who was three months pregnant at the time, withdrawing cash from an ATM inside a Walgreens store in Chatham. It's the last known images ever recorded of Coles before she vanished in October 2018.

Just minutes earlier, video shows Coles driving off from her apartment with a man detectives call a person of interest.

That same man returned to Coles' apartment the next day and left her car parked outside.

In the video posted to the CPD's YouTube channel, Coles' mother makes an emotional plea for answers.

"Is she safe? Is she hungry? Is she cold? Did she have her baby? Is he or she okay? We just want Kierra brought home safe," she said.

Chicago police said the person of interest seen with Coles in those videos was questioned, and gave varying accounts of what happened that night, but no arrest has ever been made in the case.