ANCHORAGE — A career criminal who raped younger, slightly built men while incarcerated received a 40-year sentence Thursday, raising the likelihood that the serial prison rapist will die behind bars.

U.S. District Court Judge H. Russel Holland said Sabil Mujahid’s crimes were “likely as bad as I have ever seen,” leaving his victims filled with enduring terror, anguish and shame.

“The crimes were violent. They were abusive,” Holland said. “It is clear to me the defendant planned his attacks carefully.”

Mujahid, 54, who was serving a 10-year sentence for being a felon in possession of a firearm when he sexually assaulted at least four inmates, all of them Alaska Native men, could be more than 100 years old before being freed because there’s no parole in the federal system. Adding in the remaining time on his firearms conviction, he could spend another 47 ¬Ω years in prison.

The large, powerfully built man appeared at ease in the courtroom as he spoke courteously and thanked the judge for his careful attention to the case.

“I will have to pursue this matter on appeal,” Mujahid said.

Holland heard from one of Mujahid’s victims, a short Alaska Native man who cried and whose hands shook while he read a prepared statement about what had occurred in the Anchorage Correctional Center, also known as the city jail.

“As a man it makes me feel less of one to tell you I was raped by another man,” he said.

He described Mujahid as a “monster” and said he was “the worst of predators in my mind.”

Mujahid stared impassively at the man as he struggled to get through his statement.

According to prosecutors, Mujahid raped, sodomized and sexually abused four men and tried to sexually assault two others between May 3, 2009, and May 26, 2010, while incarcerated for being a felon in possession of a firearm at the Anchorage Correctional Center.

Prosecutors said Mujahid has a lengthy criminal history. He was first convicted as an adult at age 25 for attempted murder for shooting a pimp three times in Hawaii in 1980. He served more than 12 years of a 20-year sentence but was picked up for parole violations after only 67 days.

For the next 18 years, Mujahid embarked on a crime-filled, cocaine-fueled life in which he was in and out of prison, prosecutors said.