SHINGLETOWN, Calif. » Sheriff’s SWAT teams are proceeding extremely carefully as they search a rural part of Northern California where an ex-convict suspected of fatally shooting his wife and two young daughters is believed to be hiding out, authorities said today.

Given Shane Miller’s knowledge of the area in Humboldt County and ability to fortify himself, deputies were very vulnerable, Shasta County Sheriff’s Lt. Dave Kent said. Miller also is believed to be heavily armed.

"Who knows whether or not he would retaliate against officers," Kent said. "With the information we’re receiving, it ups the ante. It’s almost like warfare."

The search is focused around the community of Petrolia, which is close to where Miller’s truck was found Wednesday. Schools in the area were closed, and residents were being advised to shelter in place. Miller is believed to be on foot.

Petrolia is about 200 miles west of the site of the slayings in Shingletown, in Shasta County. The community is about 230 miles northeast of San Francisco.

Miller is suspected of fatally shooting his wife, Sandy, 34 and daughters, Shelby, 8, and Shasta, 4, on Tuesday at his home before fleeing. He previously was convicted of being a felon in possession of a gun.

Kent said Shasta County Sheriff’s deputies received a call from Miller’s house around 7:45 p.m. Tuesday, although no one was talking on the line. When they arrived, they found the victims — all three shot multiple times.

Kent said investigators had not determined who placed the call, but he said it was from one of the victims as the shooting was in progress.

Authorities have not recovered the gun, or guns, believed to have been used in the shooting, but Kent said more weapons were found in the house.

Miller may be heading to a cabin in coastal Humboldt County, where authorities have said several weapons may be stored.

In 2002, Miller was charged in San Francisco with making and selling marijuana for distribution, being a felon in possession of a firearm, possessing a machine gun and money laundering, according to court records. He pleaded guilty to being a felon in possession of a gun and was sentenced to three years and 10 months in prison. He was released in May 2007, according to the federal Bureau of Prisons.

The two-story house where the shooting took place is nestled among pine trees, with a detached garage and shed in the back. The Redding Searchlight reported that horses and llamas graze on the property.

Investigators had not determined a motive for the shooting, but Kent noted deputies had gone to the home last month on a domestic dispute call.

Schools in the rural community of about 2,000 people were locked down during the day Wednesday, and a forest harvest demonstration for local schools set for Wednesday and today was rescheduled for next week.

Miller’s two daughters both attended school in the Black Butte Union Elementary School District, superintendent Don Aust told The Record Searchlight.

The girls’ parents pulled Shelby out of the elementary school and Shasta out of the preschool programs around three to four weeks ago.