A 21-year-old man is accused of strangling a Naperville man within hours of moving in with him after answering an ad on Craigslist seeking a roommate.

Grant Muren moved in with Charles Clark, had sex with him, got into an argument, hit him with a table and strangled him, all within eight hours, DuPage County prosecutors said Saturday.

Muren took his belongings from Clark’s townhouse, tried to burn his lease and turned on the gas from the stove and opened the oven door, trying to make the 55-year-old, self-employed computer technician’s death appear to be an accident or a suicide, prosecutors said.

Clark was found dead by his girlfriend on Wednesday.

He had contusions on his face and head, and the tip of his right thumb appeared to have been bitten off, prosecutors said.

The charred lease in Clark’s home led investigators to Muren, who was pulled over by police during a traffic stop on Thursday. He agreed to speak with investigators and admitted killing Clark, according to prosecutors.

Muren, who’s charged with first-degree murder, was ordered held Saturday on $2 million bail.

His lawyer said Muren held part-time jobs and was “trying to find his way.”