For those expecting a film about Son of Sam, better adjust your expectation. The serial killer case is little more than wallpaper here, instead we follow a couple of clowns who are trying to deal with their own troubles, with the Son of Sam case merely playing out in the background. I guess that explains the title.
Vinny is a young guy who has made a downright mess of his life. He cheats on his wife, he gets pushed around by some local wannabe mobsters and his best friend just turned into a punk lover. Meanwhile, a serial killer is on the loose in New York and starts killing people in Vinny's neighborhood.
Performances are decent but not good enough to carry the film, the characters are somewhat annoying, the film is too long and the soundtrack is lazy. Lee's direction is a notch above Scorsese's (who I think could've been in the running for this script too), but in the end Summer of Sam is overly long and just not interesting enough.