SHINGLETOWN, Calif. (AP) - A sheriff's official says the Northern California search for an ex-convict suspected of fatally shooting his wife and two young daughters is akin to warfare. Shasta County Sheriff's Lt. Dave Kent says SWAT teams were proceeding extremely cautiously on Thursday in the area near the Humboldt County city of Petrolia where 45-year-old Shane Miller's truck was found the previous day. Petrolia is about 200 miles west of the site of the slayings in the Shasta County community of Shingletown. Kent says Miller has knowledge of the area and the ability to fortify himself, so deputies are very vulnerable. They also believe he is armed. Miller is suspected of killing his 34-year-old wife, Sandy, his 8-year-old daughter, Shelby, and his 4-year-old daughter, Shasta.