A motorist who shot dead two environmental protesters blocking a road in Panama on Tuesday is a retired American lawyer, it has been revealed.

Kenneth Darlington, 77, appeared before a judge in the town of La Espiga on Wednesday afternoon, and after a two-hour hearing was remanded in custody. 

According to local media, the Panamanian-born US citizen - who was seen in both video and pictures shooting dead two teachers blocking a road on a highway - has a previous conviction for illegal possession of a firearm.