OAKLAND -- A 17-year-old boy who was shot two weeks ago was pronounced dead Friday afternoon, his aunt said.

Isaac Johnson, a junior at Berkeley High School, had been on life support since the May 11 shooting, and was pronounced dead about 2:30 p.m. Friday, said his aunt, Kaye Hudson of Berkeley.

He was the 41st homicide victim in Oakland this year.

Police have not made any arrests and a motive in the shooting was not known Friday.

The shooting happened about 10 p.m. May 11 in the 6100 block of Adeline Street about one block from the Berkeley border in area where there are homes and businesses. The teen was found on the sidewalk with a gunshot wound to the head and other wounds, authorities said.

Police still don't know what the teen was doing when he was shot.

Police and Crime Stoppers of Oakland are offering up to $10,000 in reward money for information leading to the arrest of the gunman. Anyone with information about the shooting is asked to call investigators at 510-238-3821 or a tip line at 510-773-2805.

Reach Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.