TACOMA, Wash. -- An ad on Craigslist was the bait, and a mother and son were the victims.

On Monday night, the mother and son responded to a post advertising a car for sale. They went to an apartment complex near Tacoma Mall just south of 84th Street to meet the seller.

But when they arrived, there was no car. There was only a man with a hammer, waiting to rob them.

Tacoma police said the victims had arrived at 10 p.m. with cash in hand, ready to cash in on a deal that seemed to good to pass up -- a used Honda Accord offered at $5,000 they managed to negotiate down to $3,600.

When they met and shook hands with the alleged car owner, police said, the man pulled out a hammer and attacked.

The man began going after the son with the hammer while the mother hid, detectives said. Moments later, the attacker gave up and fled. Police later found his hammer nearby.

Residents of the Waterfall Apartments were shocked to hear about the alleged attack. They didn't witness the incident, but they did see the two victims leave, all bandaged up.

"I'm real shocked. Devastating, actually," said neighbor Mimi Morris.

Investigators don't believe the attacker lives at the complex; they believe he simply used the location to lure his victims.

Anyone with information on the case is urged to contact police immediately.