RALEIGH, N.C. (WNCN) — A man serving life in prison for a 2004 murder in Cumberland County has officially been charged in the Wednesday assault and killing of a female corrections officer at a North Carolina prison, according to court documents.

Craig Clifford Wissink, 35, is facing a first-degree murder charge in the death of Sgt. Megan Lee Callahan, 29, of Edenton.

Callahan responded to a trash can fire in a living area and was attacked by Wissink around 5:30 p.m. at Bertie Correctional Institute, according to officials.

Wissink took a fire extinguisher from Callahan and assaulted her with it.

She died at 6:20 p.m. from injuries sustained during that assault.

Court documents reveal that Wissink, who had served time in Raleigh’s Central Prison before being moved to Bertie, has now been moved back to Central Prison, according to his arrest warrant.

“I am deeply saddened and send my heartfelt sympathies to Sgt. Callahan’s family,” Public Safety Secretary Erik A. Hooks said. “We will do all we can to support her family as well as the correctional family. The department will cooperate fully with the law enforcement investigation as well as conduct its own internal investigation.”

On Thursday, Gov. Roy Cooper ordered all North Carolina flags at state facilities be flown at half-staff until sunset on Friday in tribute to Callahan.

Callahan had been with the North Carolina Department of Public Safety since 2012. She was promoted to sergeant in February 2016.

Thursday, her friends in Edenton couldn’t believe the news.

“I was hoping [the news] was wrong because she meant a lot to a lot of people,” lifelong friend Michelle Rowell told WAVY.

Rowell described Callahan as a humorous person, but more like family to her friends.

The State Bureau of Investigation has been asked to conduct a full investigation into Callahan’s death.