Boston police on Tuesday identified the man found fatally shot Friday in a Jamaica Plain home as Mariano Malave of Boston. Malave was found about 6:30 p.m. in a multifamily house at 132 Hyde Park Ave., police said. He was pronounced dead at the scene. No arrests have been made. Two Sundays ago, friends and family surprised Malave with a party to celebrate his 25th birthday, said his cousin Evelise Alicea.