Nathan Middleton, 29, allegedly detailed the plan in a letter to his mother from the Rock County jail, WISC-TV, Madison, reported. A complaint was filed Wednesday about the alleged escape attempt.
Middleton was arrested in November and was being held in lieu of $100,000 bail. He allegedly told police he met Aprina Paul, 18, on Craigslist and she came to his home in late October for paid sex.
He told investigators he found Paul dead the next morning and burned her body because he was on probation, charging documents say. The cause of Paul's death has not been determined.
Another inmate at the jail tipped off a guard Dec. 1 that Middleton was trying to get help with his escape plans from other prisoners.
The next day, he allegedly talked about the letter in a phone conversation with his mother.
"If you can't do what's in that letter I'm just going to end it," he allegedly said as a detective listened in.
In the letter, Middleton allegedly told his mother to rent a car, change the license plates and leave the car running outside the jail -- and then blow a hole in the wall.
David O'Leary, an assistant district attorney, said there is no evidence Middleton's mother took any action to help him.