Boston ? A serial thief with a penchant for knocking off gourmet chocolate shops and ice cream parlors is anything but sweet, police say.

The man police have dubbed the Bonbon Bandit is wanted in as many as 20 holdups in downtown Boston since April 17. He has brandished a knife, a handgun and even a sawed-off shotgun.

“I think he’s extremely dangerous,” Detective Sgt. Richard Ross said.

The robber tends to target businesses that are generally staffed by women and not monitored by security cameras, police said. Besides seven gourmet chocolate and ice cream shops, the Bonbon Bandit is suspected of robbing gift shops, stationery shops, a dry cleaner’s and a candle store.

The bandit, Ross said, is a black man in his late 30s or early 40s, 5 feet 8 inches tall, 140 pounds and clean-shaven.