The Somerset County sheriff personally implored suspected police-killer John Williams to turn himself in Thursday morning, and hours later a massive law enforcement presence converged on a rural road in Fairfield.

Cpl. Eugene Cole, 62, of the Somerset County Sheriff’s Department, was shot and killed early Wednesday on U.S. Route 2 in Norridgewock. Cole has a son, David, who is also employed as a deputy by the sheriff’s office.

The shooting marked the first Maine police officer was killed in a shooting in nearly 30 years.

The suspect, who remained at large and is considered by police to be “armed and extremely dangerous,” was identified as John Williams, 29, of Madison. He was described as being 5-foot, 6-inches tall, weighing about 120 pounds, with brown hair and blue eyes. Police said anyone who sees Williams should call 911 immediately.

Around 10 a.m., more than 20 police cruisers were racing toward Fairfield in the area of Martin Stream Road — the apparent epicenter of Thursday’s search efforts. A major police presence could be seen on Bear Mountain Road, a dirt road off Martin Stream Road, that travels through a heavily wooded, swampy area. Some two dozen police vehicles were parked along Bear Mountain Road amid steady rainfall.

More police units arrived around noon, as the dirt road was blocked off with yellow crime scene tape. Assembled members of the media were told to move away from the road entrance. Around 12:20 p.m., an armored state police vehicle entered Bear Mountain Road.

During a morning press conference in Norridgewock, Somerset County Sheriff Dale Lancaster said officials continued to work overnight and into the morning, increasing patrols in the area and following up on leads. A police command center has been set up near the Norridgewock Fire Department.

“This was a senseless act against a committed public servant. Our hearts are very heavy for all law enforcement in this state,” Lancaster said. ” …. I’m asking John Williams, personally, if you are listening to my words today, please turn yourself in.”

Some 175 to 200 officers among local, state and federal agencies are involved in the search effort to find Williams, the sheriff said.

Several law enforcement agencies — including the Somerset Sheriff’s Office, FBI and Maine State Police Major Crimes Unit — converged Wednesday night outside a house on Jones Street in Madison, apparently to execute a search warrant. But authorities appeared to leave the location after several hours with no noticeable outcome or announcements in the case.

Lt. Col. John Cote of the Maine State Police said during Thursday morning’s press conference that officials executed the warrant at Williams’ last known in Madison to gather more information and evidence. Cote asked that if anyone has had contact with Williams, including via text message or social media, to contact authorities.

Police believe it’s Williams is likely still in the area and they have no information suggesting he’s “gone mobile,” so the public should be cautious and keep vehicles locked, Cote said.

Authorities said Cole was shot between 1 and 2 a.m. and his body was found at 7:15 a.m. Wednesday at 16 Mercer St., which is also U.S. Route 2, in Norridgewock. It was unclear Wednesday under what circumstances Cole and Williams encountered each other during the early morning hours, and authorities declined to say any more, citing the ongoing investigation.

Lancaster said Wednesday that Williams stole Cole’s fully marked cruiser, then drove to the Cumberland Farms store, where he reportedly committed a theft. He then fled in Cole’s cruiser.

Cole’s cruiser was found abandoned shortly after 5 a.m. off Martin Stream Road in Norridgewock, police said, and they believe he then fled the vehicle on foot.

A nationwide alert had been issued for Williams and that police did not know of any vehicle Williams might be using after allegedly abandoning the police cruiser.

Steve McCausland, spokesman for the Department of Public Safety, said Cole is the first officer killed in a shooting since Giles Landry was shot in an incident in Leeds in 1989. However, McCausland said there have been several officers who have been killed in the line of duty in the years in between, including most recently, Nathan Desjardins, a Fryeburg police officer who died from injuries sustained last summer while trying to save a boater’s life in the Saco River.

Williams has a scant criminal history in Maine, where records indicate he was born in Texas.

Williams was arrested in Massachusetts last month on firearm charges, and was scheduled to appear Wednesday in a Massachusetts courtroom for a probable cause hearing, according to the Essex District Attorney’s Office.

According to the State Bureau of Information, the agency that maintains criminal records in Maine, Williams was charged with Class C felony burglary when he was a juvenile. He was found responsible for the offense Feb. 13, 2006. Williams served 17 days in an unspecified correctional facility, was placed on probation for a year and was ordered to pay $500 in restitution. The date of the offense and his age at the time was not provided. Although most juvenile criminal records are confidential, state law mandates that Class C felonies, punishable in the adult system by up to 5 years in prison and a $5,000 fine, remain public.

This story will be updated.