Police searched Friday for a man suspected of fatally stabbing his estranged pregnant wife, a Customs agent, at her South Bay apartment while their two young children were nearby.Jesus Arteaga Garcia of National City knocked at the front door of 28-year-old Maribel Arteaga's residence on Santa Alicia Avenue in Chula Vista just before 8:30 p.m. Thursday, then allegedly attacked her with a long-bladed hunting or fishing knife when she answered, authorities said. The couple's children, ages 6 and 7, were home at the time.Medics took the woman, who was two months pregnant, to Scripps Mercy Hospital in San Diego, where she was pronounced dead about 90 minutes later.Garcia, also 28, may be driving a gray 2007 Ford Ranger, California license No. 8T23674, Chula Vista police spokesman Bernard Gonzales said. The pickup truck has tinted windows and a yellow-ribbon sticker in the rear window, he said.The suspect also has access to two other vehicles: a late-model white Chevrolet Cobalt LT sedan, California license No. 6HKG044; and an older blue Chevrolet minivan, Baja California license No. BCW-66-27.The victim worked at the Office of Field Operations at Tecate Port of Entry, checking incoming travelers' citizenship, itineraries and declarations of import goods. She had been employed by U.S. Customs and Border Protection since May, according to CBP information officer Angelica De Cima."We are coordinating with the Chula Vista Police Department and will assist in any way possible to bring her killer to justice," De Cima said.Garcia, who has a tattoo of a tiger on his right arm, should be considered dangerous, authorities advised.