GREENOCK star Martin Compston has spoken about his latest role playing one of Scotland’s most notorious serial killers.

The local actor returned to his hometown to film the drama series based on the crimes of Peter Manuel, which is being shown on STV this month.

Psychopath Manuel went on a two-year killing spree in Lanarkshire in the 1950s before eventually being convicted of seven murders.

He was one of the last people to be hanged in Scotland.

Compston, who plays Detective Sergeant Steve Arnott in the award-winning Line of Duty, said he read all the books written about Manuel and watched documentaries to research for the role.

He added: “It was really shocking when I started looking into it.

“I gave myself a fright in one scene because I went a bit too far, because he was so evil.

“I felt really good all the way through filming, but I just had that one moment where I took it too far.

“I went to Manuel’s house one night after filming. Just to sit outside. All the murders too places within a 10-minute radius.

“From what my aunts told me, people in Greenock were locking their doors. It put a fear right across the West of Scotland.”

He described Manuel as a ‘psychopath’ and ‘completely evil.’

Martin said: “You always have to remember his victims were real people. This really happened and he really did these things.

“When you look at the details of the story and the fact he defended himself in court, it’s insanity.  He was the ultimate narcissist.”

The actor said it was interesting to return to his hometown to shoot the drama. The star said: “My dad came down to watch filming. It was lovely to see him and to film in Greenock and see some familiar faces.”

In Plain Sight starts on STV on Wednesday December 7 at 9pm.