The third and final part of ITV's The Pembrokeshire Murders broadcasted on Wednesday as viewers watched Keith Allen's terrifying portrayal of serial killer John Cooper for the final time.

The drama was about the true story of serial killer John Cooper, who was convicted and sentenced for killing siblings Richard and Helen Thomas in 1985, and Peter and Gwenda Dixon in 1989.

In the final episode, Cooper was found guilty of his gruesome crimes and given a life sentence.

In the chilling scenes, the furious murderer was dragged out of court repeatedly shouting: "I am not a rapist! I am not a murderer."

Viewers were left horrified as they watched Keith Allen's creepy portrayal of the Bullseye killer

Viewers were left horrified as they watched Keith's terrific performance as the series came to an end.

They took to Twitter, as one wrote: "Keith Allen is horrifyingly good, isn't he?"

While another wrote: "Got to say. Not gonna be wanting to meet Keith Allen anytime soon. Like. Anytime. Soon."

"What a powerful ending to Pembrokeshire Murders and a great performance by Keith Allen who is chilling and creepy in equal measure", penned a third.

Viewers branded Keith's terrific performance 'chilling' and 'creepy'

During the gripping final episode, Detective Superintendent Steve Wilkins (played by Luke Evans) finally found the evidence he needed to arrest Cooper.

They discovered the victims blood on a pair of Cooper's khaki shorts which he previously said belonged to him.

Cooper had a long history of crime, including 30 robberies and violent assault.

Actor Luke Evans played Detective Superintendent Steve Wilkins in the three-part series

In 1998, he was sentenced to 14 years for burglary and robbery but was released in 2009.

Following a cold-case review which started in 2005, he was eventually arrested and convicted of the two double murders in 2011.

He was convicted for the murders of Richard and Helen Thomas, and Peter and Gwenda Dixon.

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