Fifth Woman 1I Found in L A.Murder Victim 1Mother of 3 Dead; Mate Of Victim Four Arrested1ItfI\iLOS ANGELES, May 12,— (A*—A fifth sex slaying left officers today with a new mystery murder, only a few hours after the husband of the fourth was boohed on suspicion ofmurder.A strip from a pair of men’s blue and white shorts knotted around her neck, the body of i!,petite, brown-haired woman was1 i discovered today in an oil field near 1 Long Beach, She had been stran-0 i gled and, police said, apparently raped. But, unlike other victims in a wave of homicides which began in January with the “Black Dahlia” bisection, she had not been mutilated,Police identified her as Mrs. Laura Elizabeth Trelstad, 37, 2211 Locust street, Long Beach. They said her husband, Ingman, a truck driver, reported she left a party j s which they were attending late • yesterday afternoon, announcinglrnr'S10‘PI1IiIIthat she was going to * dance. TheT]petite Mrs. Trelstad’s body was j found not far from her home, on a I lonely road leading to a Signal Hill „ ioil field. She was the mother of* three children, the eldest 9 years* I old,| Her expensive looking peacock blue dress was torn, as were her urtderthings. One white shoe was missing. Police Sergt. Howard H. Sweet said tire marks and footprints indicated she might have ■ been killed elsewhere.Clothing Ton Police Sgt, Howard H. Sweet said today’s victim was clad in an ex-pensive looking peacock blue dress,which was ripped away at the front. Her brassiere and underclothing also were torn, One white, open-tie shoe was missing, A three-quarter (Tuna to Page t, Column t)e-I’Sii-iereteKid{0red-oftoiIj1itlIJ