The 33-year-old Scottish actor better known as Heartbeat‘s PC Joe Mason finds himself on the other side of the law in his new role in Casualty.

Joe will become a semi-regular character of the hit BBC hospital drama when season 24 airs this autumn. He’s been cast as Alistair, a homeless man who comes into contact with naive paramedic Polly Emmerson (Sophia Di Martino) as part of her first major storyline since joining the medical series.

Talking on the Paul O’Grady Show earlier this week, he revealed: “I play a very dodgy guy, quite damaged from living on the streets, who is not as nice as he first seems.”

Cash-strapped ITV bosses have axed Heartbeat, although the show will continue to air until 2010 as enough advance episodes have been filmed.

Casualty is not showing on Saturday, May 16, due to live coverage of the Eurovision Song Contest 2009.