NORRIDGEWOCK (CBS) – A massive manhunt is underway for an “armed and extremely dangerous” man wanted for fatally shooting a Maine sheriff’s deputy and stealing his cruiser early Wednesday morning.

Just before 2 a.m., police say 29-year-old John Williams stole Somerset County Cpl. Eugene Cole’s fully marked police cruiser. Cole was killed during the incident, though police did not say when.

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Norridgewock, Maine. (WBZ-TV Graphic)

Police say Williams drove the cruiser to Cumberland Farms on Waterville Road in the central Maine town of Norridgewock and robbed the store. He then allegedly drove away in the cruiser.

The cruiser was located around 5 a.m. Williams remains at large and is considered armed and extremely dangerous.

“Many times we’re able to say there is not an ongoing threat. That is not the case today. There certainly is an ongoing public threat,” Maine State Police said.

Despite a nationwide alert, authorities seem focused on a few small towns in Central Maine. Heavily armed officers surrounded a home in Madison Wednesday night. It was Williams’ last known address. Police executed a search warrant, but the suspect was not located.

John Williams seen on dashboard camera leaving the Cumberland Farms he is accused of robbing. (Image Credit: Maine State Police)

Williams is described as 5’6” tall, about 120 pounds with brown hair and a ponytail. Anyone who sees him is asked to call 911 and not approach Williams.

Massachusetts State Police arrested Williams on March 22 in Haverhill. Police found Williams’ car in a ditch on Route 495.

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When they searched his car, troopers found an unlicensed gun. He was arrested on several charges, including possession of ammunition without an FID card and possession of a large capacity feeding device.

John Williams is suspected of killing a Maine sheriff’s deputy. (Image Credit: Maine State Police)

A Haverhill District Court clerk confirmed that Williams was scheduled to appear on Wednesday for a pre-trial hearing.

During Williams’ arraignment on March 22, prosecutors requested $10,000 bail. A judge set bail at $7,500, but after a review hearing on March 27 it was lowered to $5,000. He posted bail on March 31.

Cpl. Eugene Cole. (Image Credit: Augusta Police)

Somerset County Sheriff Dale Lancaster said Cole was a veteran member of the department.

“This is a very sad day for the Somerset County Sheriff’s office, the citizens of this county, and people of the state of Maine,” Lancaster said. “We have lost an outstanding deputy today who served with great distinction for the last 13 years.”

A nationwide bulletin has been issued as police search for Williams. The search is ongoing on the ground and in the air with a State Police helicopter.

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“We have been following up on numerous leads throughout the day. There has been a large contingency of officers from different law enforcement disciplines working leads. If anyone knows the whereabouts of John Williams, please give us a call,” said Maine State Police at news presser Wednesday evening.