The Mississippi Bureau of Investigation said Sunday that a man has been charged with capital murder in the shooting death of a 77-year-old deputy sheriff who was taking him to a mental health facility.

Joaquin Blackwell, 22, of Magee was arrested Saturday in Simpson County, a day after the fatal shooting. After an extensive manhunt, Blackwell was caught behind a gas station near the Region 8 Mental Health Services building.

Blackwell was being taken to the facility under a court order Friday. Simpson County Sheriff Paul Mullins said investigators believe Blackwell took a gun from deputy James Blair, shot him and ran into the woods.

It was not immediately clear Sunday whether Blackwell is represented by an attorney. He was in custody in nearby Rankin County.

MBI said Sunday that an investigation continues to determine whether anyone helped Blackwell evade law enforcement officers during the search for him.

Blair had continued to work to provide for grandchildren he and his wife were raising, news outlets reported. He had also worked as a school crossing guard.

“We have lost a true public servant and a great man,” the Simpson County Sheriff’s Department said Saturday on its Facebook page.

Dave Van, the executive director of Region 8 Health, had told WJTV that Blackwell was in the custody of the sheriff’s department when he was being brought to Regions 8 Health for an evaluation. Family members had been concerned about his mental health.