Don’t mess with a man’s hat.

A 22-year-old man was robbed of his baseball cap in the Mission district on Monday, police said.

The victim was in the 2400 block of Mission Street around 9 p.m. when a man in his 20s grabbed the hat right off his head, police said. The alleged hat thief then made some kind of gang sign and fled on foot.

Hours later the victim approached San Francisco police who were investigating an unrelated case and pointed out the suspect who was milling about in a crowd of onlookers, police said.

Police arrested the suspect.

rnagle@sfexaminer.com