Cab Driver Believes He Saw Mrs. TrelstadAnother witness who believes he j saw Mrs. Laura Trelstad on the! night before her murdered and! violated body was found on a vacant lot, yesterday told his story to police.He was George Sylva, taxicab driver, 330 Ohio avenue. Sylva related he was driving south on Long Beach boulevard, 100 feet north of Wardlow road, when he saw a small woman dressed in a dark coat staggering down the street.Believing he might have a fare,! he 1 urned his car around and asI he did so he saw a man in a 193?: or 3938 tan colored Willys coachj stop and pick up the woman, he Itold Detective Inspectors E. IL Kennedy and Fred Whitmore.Sylva said this happened at 11:30 p. m. on May 11. Mrs. Trelstad, 37, mother of three children, was found choked to death on a vacant lot in the .3100 block of Locust avenue early the next morning,Whitmore and Kennedy said Clove Dowdy, 223 East 67th street, driver of a Huntington Park-bound bus, and passengers on his bus believe Mrs. Trelstad got off the bus at Long Beach boulevard and Wardlow road at approximately 11:25 p. m., or five minutes before Sylva said he saw the woman.