St. Paul police are asking for the public’s help to find a man who stole a cellphone out of a 9-year-old girl’s hand this week.

It happened as she waited for her younger sister to get off a school bus in Frogtown on Tuesday about 3:25 p.m., said Steve Linders, a police spokesman. The child was uninjured, he said.

The man grabbed the phone, valued at $100, from the girl on the southeast corner of Grotto Street and Edmund Avenue and said, “Ah-ha, I got your phone,” according to Linders. He then ran away with it.

“Stealing a person’s cellphone is bad enough, but grabbing a phone out of the hands of a 9-year-old is absolutely despicable,” Linders said.

A nearby surveillance camera recorded the thief, and police posted a screengrab on Facebook on Wednesday, asking anyone with information about his identity to call the case investigator at 651-266-5416.

The suspect is described as black, in his mid-to-late 20s, 5 feet 9 inches tall, with a medium to stocky build. He had a beard and glasses and was wearing a black knit hat, a Carhartt-style jacket and dark-colored jeans.

Mara H. Gottfried can be reached at 651-228-5262. Follow her at twitter.com/MaraGottfried.