DETROIT (AP) — An 18-year-old convicted of killing another man, then beheading him and setting fire to his body in what prosecutors called a thrill killing was sentenced Monday to life in prison without parole.

Jean Pierre Orlewicz of Plymouth didn't speak in court before being sentenced to the mandatory prison term. But Wayne County Circuit Court Judge Annette Berry said she was grateful he was convicted.

"I am grateful that you are going away for the rest of your life, because in my view I believe you will kill again," Berry said.

Orlewicz was convicted last month of first-degree murder in the Nov. 7 slaying in Canton Township of Daniel Sorensen, 26, of River Rouge.

Sorensen's father, James Sorensen, called the killing "the ultimate act of cowardice." As James Sorensen choked back tears, he told the court: "My son was a victim of a person seeking a trophy."

The defense had argued that Orlewicz killed the much larger Sorensen in self-defense and mutilated the body because he feared reprisal by organized crime figures. Orlewicz took the stand in his own defense at trial.

Orlewicz's lawyer, James Thomas, said he plans to appeal the conviction and instructed Orlewicz not to speak Monday because of the appeal.

"We had a different view of this trial," Thomas said. "It was a hard fought case."

Prosecutors, however, said Orlewicz carefully planned the killing as shown by the 13 knife blows used to kill Sorensen.

The judge called the killing "an evil act." ''There is a difference between mental illness in this country and evil," Berry said. "But your actions, sir, are tantamount to evil. No two ways about it."

Alexander Letkemann, 18, of Westland, pleaded guilty to second-degree murder in the slaying just before the trial. He testified that Orlewicz, who was his friend, slit Sorensen's throat and repeatedly stabbed him.

Letkemann was sentenced to 20 to 30 years as part of a plea deal.