A UK monster accused of stabbing a 13-year-old girl “execution-style” because she threatened to reveal that he had been sexually abusing her has been sentenced to at least 33 years behind bars, according to a new report.

Stephen Nicholson, 25, described as a “predatory pedophile,” was a lodger at Lucy McHugh’s home, The Guardian reported.

He lured Lucy into the woods in Hampshire about a year ago and stabbed her 27 times before tossing the weapon and trying to burn his clothes, according to the report.

As she issued the sentence, The Hon. Mrs. Justice May told Nicholson that his crime was “a pitiless attack on a child following months of sexual exploitation.”

“It seems Lucy developed a crush on Nicholson,” May added, according to the report. “Instead of rebuffing her, he encouraged her to continue her interest in him. He took full advantage. Nicholson used and abused Lucy. She had ceased to be of interest to him and had become an obstacle to his comfortable life.”

“There was also the real risk of her making good on her threat to out him as a pedophile,” the judge added. “As far as he was concerned, she had to go.”

She also called Lucy vulnerable and “easy prey,” who suffered a “particularly ferocious and brutal” attack.

After Lucy vanished, Nicholson has even sent the girl’s mother a deceivingly supportive message, telling her to keep her chin up, the paper reported. Then, as if nothing happened, he continued a project to convert a shed into a house for his pet snakes — including a 9-foot boa constrictor, according to the report.

This wasn’t the first offense for Nicholson, a care worker and an amateur tattoo artist.

Prosecuting attorney William Mousley, Queens Counsel, told the court that Nicholson had been sentenced to two years behind bars at only 14-years-old for holding both youngsters and staff at a children’s home hostage at knifepoint. He was under the influence of amphetamines at the time, according to the report.

“He said he was intoxicated and experienced a feeling of power when he committed the offenses,” Mousley said.

He was also sentenced to 14 months last August for refusing to share his Facebook password to authorities investigating Lucy’s murder, the paper reported.