An 18-year-old suspect wanted in connection with the shooting death of an Alabama sheriff was taken into custody very early this morning following a nearly four-hour manhunt.

William Chase Johnson, who authorities said earlier had driven off in the sheriff’s vehicle after the 8:15 p.m. shooting returned to the crime scene with a firearm in his hand and surrendered.

Fatally shot Saturday evening was Lowndes County Sheriff John Williams Sr., known as “Big John,” a U.S. Marine Corps veteran who had been sheriff in the community near Montgomery, the state capital, for nearly a decade.

Williams had responded to a call from a convenience store in Hayneville, about 24 miles southwest of Montgomery, when he was fatally shot. Further details of the incident were not immediately available.

Authorities quickly posted an online alert about Johnson, with the Alabama Law Enforcement Agency describing the suspect as “a serious risk to the public.”

After Johnson allegedly drove off in the sheriff’s vehicle, it was later spotted abandoned and was recovered.

A heavy law enforcement presence was seen at the convenience store following the shooting.

Williams was first elected sheriff in 2010 and has held the job ever since. His death was quickly recognized as a severe blow to the community he served.

Alabama Governor Kay Ivey posted a Twitter message in reaction to the sheriff’s death.

“I’m saddened to hear about Sheriff Big John Williams, who was tragically killed this evening in the line of duty,” Ivey wrote. “Through his service to our country in the @USMC and his many years working in law enforcement, he dedicated his life to keeping other people safe.

“He will be remembered as a consummate professional and pillar of his community,” Ivey continued. “I offer my prayers and deepest sympathies to his family and to the men and women of the Lowndes County Sheriff’s Department.