The family of a man who was shot dead in West Lothian have said he was "deeply loved" as police confirmed the arrest of a fourth suspect.

Billy Watson, 35, was fatally injured in a property on Harestanes Road, Armadale, at about 11:50 on 12 September.

Three men have already appeared in court charged with murder and attempting to defeat the ends of justice.

On Tuesday officers said a 20-year-old man had also been arrested in connection with the death and inquiries were ongoing.

A family statement, released through Police Scotland, said: "Billy was a deeply loved son, dad, brother, uncle and friend.

"We are all desperate to find out any information about this horrific incident."

Frank McCarthy, 57, Corrie McQueen, 29 and Martin Patterson, 44, previously appeared before Livingston Sheriff Court charged with murder and attempting to defeat the ends of justice.

They made no plea and were remanded in custody.