Police were called to a SeaTac Bank of America at noon after getting reports of an armed robbery in progress.
When they arrived at the bank, located in the 16600 block of International Boulevard South, they were told the robber was still inside. Officers surrounded the building, and a few minutes later a man walked out with his hands in the air.
The suspect, who was identified only as a 49-year-old California man, was arrested without incident. Detectives say he left his gun inside on a chair before walking out of the bank.