Builder Slain in New Home by Intruder : Homicide: Gunman entered through doors left open because of heat. Man found jumping over fences in neighborhood is held.

Los Angeles homicide detectives Monday were investigating the slaying of a San Pedro builder who was shot and killed Sunday night in his new home by an intruder who entered through family room doors left open because of the recent heat wave.

Hours after the killing of Richard Mavar, 30, detectives said they still were interviewing a man arrested in the neighborhood during a search that followed the 11 p.m. slaying. The man, who was not identified by police, was picked up by officers after they found him jumping over fences in the quiet neighborhood where Mavar had lived since April in a home he had built.

Authorities were not certain of the motive for the attack.

The slaying of Mavar, whose family is well known in San Pedro for building homes and office buildings, stunned the community. “It’s really a shock,” said Harbor area Councilwoman Joan Milke Flores, noting that Mavar lived in one of the community’s most affluent and tranquil neighborhoods.

According to police, Mavar and his wife, Cameran, were sitting in the family room of their home in the 1400 block of West Santa Cruz Street when the intruder, armed with a rifle, burst through French doors leading from the back yard.

After yelling to his wife to summon police, Mavar struggled with the gunman before being shot several times, police said. The gunman then fled. Mavar was pronounced dead at the scene.

Homicide Detective Paul Mize said a motive for the slaying remained unclear because the gunman may have fled the house without taking any valuables. “We think he must have taken something, but we don’t yet know if anything significant is missing,” Mize said.

Mize also said detectives were not sure if the man in custody was responsible for the slaying.

“We’ve kept him for questioning though we don’t know if he’s the intruder or just a prowler who got caught while we were searching the neighborhood,” Mize said.

The victim’s wife, Mize said, told investigators the couple had opened the doors because of the heat.

“We all know better and yet we all do it,” said Detective Pat Marshall.