Kentucky State Police are searching for motive as they investigate the fatal shooting of a district judge by a sheriff after the two had an argument inside the judge’s chambers, according to police.

A sheriff is charged with first degree murder after a district judge was shot and killed inside the Letcher County Courthouse in Whitesburg, Kentucky, police said.

Blue lights flashed in the background Thursday night as a Kentucky state trooper gave reporters details that state police had pieced together about a judge’s courthouse shooting death — allegedly by the county’s sheriff.