GRAND RAPIDS, Mich. - More than two decades after then 16-year-old Federico Cruz killed and beheaded a teen near Sparta, the “savage butchery’’ of the crime and a history of antisocial behavior precludes him from ever leaving prison, a judge ruled Wednesday.

His juvenile record and the “outrageous behavior both with regard to the murder and the mutilation’’ justifies life in prison rather than a term of years, Kent County Circuit Court Judge Dennis Leiber ruled.

Cruz was 16 when he killed 17-year-old David Crawford, severed his head and recorded himself dissecting the head. Cruz said he did it to please Satan.

“Several of the doctors have gone to some length to try to describe the horror of this savage butchery,’’ Leiber said. “Federico Cruz experienced pleasure in what he did. He said it and the video confirms it. He has a substantial personality disorder.’’

Defense attorney Andrew Rodenhouse had sought a term of years rather than life in prison. He said Cruz has made strides to better himself while in prison and is remorseful for his crime.

“Is Mr. Cruz so irredeemably corrupt he can never be rehabilitated? I don’t believe that,’’ Rodenhouse said.

Crawford’s family attended Wednesday’s hearing. His mother, Juliet Crawford, said it was difficult to rehear details of David's grisly death, but said she is grateful the life sentence imposed nearly 21 years ago was upheld.

“I certainly don’t want this individual to be released so he can hurt somebody else,’’ Juliet Crawford said. “He has the propensity because he was thinking about killing somebody at 16 years of age and he knew how he wanted to do it. When you have that mindset at 16, you should never be let out of prison.’’

A Kent County jury in 1997 convicted Cruz of first-degree murder for the April 1996 crime. Leiber, who presided over the trial, sentenced Cruz to mandatory life in prison.

That sentence was upended when the U.S. Supreme Court in 2012 struck down mandatory life sentences for juveniles. It said life sentences are still an option, but only under the rarest of circumstances.

The Kent County Prosecutor’s Office two years ago filed motions to impose no parole sentences on 13 defendants serving life terms for murders committed as teens. Prosecutor Chris Becker says Cruz topped the list.

“This was about as horrific as it could get,’’ Becker said.

Leiber agreed. The judge rattled of a litany of offenses Cruz committed as a child, including poisoning a container of milk, arson, theft, sexually inappropriate behavior with relatives and animal torture.

The antisocial behavior leading up to the murder included expulsion from school and a "regrettably lengthy'' juvenile court record, Leiber said.

“I’ll not articulate everything that was done,'' Leiber said. "It was not anything that was idle; it was intentional. It wasn’t anything that was spontaneous. It was planned. It was a cold, calculated, almost clinical dissection of this man’s head.’’

Police learned about the crime on April 29, 1996 after Jose Cruz contacted Sparta police to report his son may have committed a murder.

The father learned from one of his son’s friends that Federico committed a murder and it was on videotape. The Kent County Sheriff’s Department searched the Cruz home on Schultz Street east of Alpine Avenue NW.

Officers found a white plastic bag behind the house containing a human head. Deputies then spoke with Federico Cruz in the basement of his home for about 90 minutes.

Cruz told detectives he did not know the victim. He said he saw Crawford walking down railroad tracks by the Cruz home and “bummed’’ a cigarette from him. Cruz told Crawford about growing marijuana plants in the woods.

Cruz took the teen to where the plants were located, and, according to Cruz, went into a rage when Crawford stepped on one of the plants.

He started to strike Crawford in the head, knocking him down. Cruz then kicked him in the head several times and stepped on Crawford’s throat “crushing his windpipe, killing him,’’ court records show.

“Federico felt little remorse for what he had done. He stated that he felt remorseful for just a couple seconds,’’ Becker wrote in his request that Cruz be sentenced to life without parole.

Cruz admitted to cutting off Crawford’s head several hours after the killing. “He told detectives he wanted a skull, a real skull to use as a decoration,’’ Becker wrote. “Federico tried to cut out David’s heart after the murder, as well as the spinal cord.’’

Cruz took the severed head back to his house “and proceeded to dissect it,’’ Becker wrote. “He set up a video camera and taped himself doing it.’’

The video shows Cruz mutilating the head as loud music plays in the background. He also provides commentary during the mutilation and refers to the recording as "another f------ episode of the murder show.’’

Deputies recovered Crawford’s headless body in a swampy, wooded area propped up against a tree. There were 17 stab wounds in the chest and back and a ‘gaping area’ in the lower chest and abdomen area. The wounds were inflicted after Crawford was dead.

In subsequent interviews, Cruz indicated he heard ‘voices coming out of a poster in his room to go kill.’ Cruz also said he heard voices in jail telling him to kill himself and others, court records show.

At trial, his attorney launched an insanity defense. The jury did not buy it.