The estranged husband of a missing Point Loma Heights woman is a person of interest in her disappearance, and detectives searched his home Friday, police said.Rosa Lisowski, 48, has not been seen since about 7:30 a.m. Monday, when she walked her son to Barnard Elementary School, according to the San Diego Police Department.The mother of three did not have her wallet, identification or money with her at the time, officials said.On Friday, investigators searched the Ocean Beach home of the woman's estranged spouse, Henry Lisowski. The couple is in the midst of a divorce and child-custody dispute, and the woman earlier said her husband threatened her, authorities have said.In response to questions from reporters outside the man's West Point Loma Boulevard house, SDPD Lt. Terry McManus described Henry Lisowski as a person of interest in the case."In any investigation, certainly any missing-persons investigation, (some) of the first people that we speak to are the family and friends, or in this case the ex-husband," he said. "We've spoken to him several times. He'll continue to be a person that we'll speak with throughout the investigation."Rosa Lisowski is a Latina, 5 feet 2 inches and about 165 pound, with black hair and brown eyes.She was last seen wearing dark-colored sweat pants, a black hooded jacket and leather "flip-flop" shoes, police said.Anyone with information on Lisowski's whereabouts was urged to call police at 619-531-2000.