A man and a young boy have been killed in a shooting near Pittsburgh and three people have been arrested. Allegheny County police say the shooting happened yesterday in Swissvale. When police arrived, they found a 29 year old man dead and a seven year old boy wounded. The boy was taken to a Pittsburgh hospital, where he later died. Police say the shooting appears to have been an exchange of gunfire. One of the three arrested was wounded and taken to a hospital.