A Kentucky sheriff has been arrested after fatally shooting a judge in his chambers, police say.

District Judge Kevin Mullins died at the scene after being shot multiple times in the Letcher County Courthouse, Kentucky State Police said.

Letcher County Sheriff Shawn Stines, 43, has been charged with one count of first-degree murder.

The shooting happened on Thursday after an argument inside the court, police said, but they have not yet revealed a motive.

Officials said Mullins, 54, was shot multiple times at around 14:00 local time on Thursday at the court in Whitesburg, Kentucky, a small rural town about 150 miles (240km) south-east of Lexington.

Sheriff Stines was arrested at the scene without incident, Kentucky State Police said. They did not reveal the nature of the argument before the shooting.

The state attorney general, Russell Coleman, said in a post on X, formerly Twitter, that his office “will fully investigate and pursue justice”.

Announcing Judge Mullins’ death on social media, Kentucky Governor Andy Beshear said: “There is far too much violence in this world, and I pray there is a path to a better tomorrow.”

Kentucky State Police spokesman Matt Gayheart told the Washington Post that 50 employees were inside the court building when the shooting occurred.

No-one else was hurt. A school in the area was briefly put on lockdown.

Mr Gayheart, who has worked with Kentucky State Police for 14 years, added: "This is the only incident like this I've heard of in this county."

Kentucky Supreme Court Chief Justice Laurance B VanMeter said he was "shocked by this act of violence".