Residents who got fed up with the sound of hammering at 2 in the morning at Morton Street and Blue Hill Avenue in Mattapan finally called police, who say officers and Nitro the K-9 dog found a Dorchester teen inside the walls of a vacant building on Blue Hill Avenue, attempting to bang his way into Boston Check Cashing next door.

Frandy Jean, 17, of Dorchester, was charged with breaking and entering a commercial business at night and possession of burglarious tools after officers pulled him out of the space between the walls of the two buildings early this morning - with the help of Boston firefighters, who arrived to make the hole Jean had allegedly made large enough to let Nitro in. In a statement, police said:

"The suspect at this point was screaming and crying stating repeatedly 'I'm sorry. I'm sorry. I did it. Don't let him bite me.' "

Police did not have to transport Jean far for booking. The check cashing place is across Blue Hill Avenue from the district B-3 station.

Police say Jean had actually been hammering away for four hours before neighbors called to complain.