TUKWILA – Police have arrested a level 3 sex offender accused of trying to kidnap a woman Thursday night in the parking lot of the Tukwila Costco.

The details of this case read like the script of a scary movie.

A woman was leaving the parking lot Thursday evening, when she says she looked in her rearview mirror and saw a man in her back seat.

Police say the woman had just finished loading her purchases into her car, and the man likely snuck into her backseat while she returned the shopping cart.

"We really want to emphasize to the public that this is a rare event," said Mike Murphy, of the Tukwila police department. "But being diligent and looking in the back of your car before you get in, even in broad daylight, is not a bad idea."

The woman spotted the suspect as she was driving away, and immediately started screaming for help.

Police say the suspect leaned forward and started assaulting her, but thought better of it and bolted out of the car.

A passer-by heard the victim's cries and started chasing the suspect.

Other people also came to help and were able to hold the suspect until police arrived.

It turns out the suspect is a registered sex offender, convicted of first degree rape in 1982.

The suspect is a level three sex offender, which means he's considered a potential high risk to the community and a threat the re-offend.

Police say the suspect was armed with a knife when the bystanders took him down.

He was booked into jail on charges of kidnapping and assault.