A double homicide at San Jose's Mexicali Club on Saturday night turned into a triple homicide Sunday morning when the body of a third man was found in a sport utility vehicle a block from the nightclub. A fourth man, also shot at the club Saturday, remained hospitalized Sunday with life-threatening injuries. Police withheld the victims' names because relatives had not yet been notified. "This is an out-of-the-ordinary, very unusual, very violent weekend," San Jose police Sgt. Ronnie Lopez said. "We will investigate each of these crimes very aggressively. We hope this is not the beginning of a trend." At the Mexicali Club, located on Oakland Road near Highway 101, a live band was performing Saturday night when someone from inside the bar called police to report that a man with a gun was trying to enter the club. When police arrived, two men were dead on the floor and another was seriously injured. About 12 hours after the shooting, a passer-by on 12th