Four convicted killers serving mandatory life sentences for murders that happened when they were teens were back in Kent County for re-sentencing Friday, each given a change at freedom when they are still middle-aged.

The sentence hearings in two different courtrooms are in response to a U.S. Supreme Court decision that ruled mandatory life terms for juvenile offenders is unconstitutional.

They are among 24 Kent County killers affected by the Supreme Court decision. Kent County Prosecutor William Forsyth is trying to keep 13 of them locked up for life.

The four who appeared in court today were convicted in three separate murders dating back to 1996. After today’s hearings, all will be eligible for parole; some sooner than others.

They are among more than 360 juvenile lifers held in Michigan prisons. Instead of mandatory life, teen killers now face a minimum sentence of between 25 and 40 years and a maximum term of not less than 60 years.

Up first was Ahmad Williams. Now 34, Williams fatally shot a rival outside Miss Tracy’s Liquor Store on Franklin Street at Neland Avenue SE in Jan. 1998. Williams was 15 years old at the time; the same age as his victim, Derrick Pimpleton.

Forsyth called Williams “a cold-blooded killer,’’ noting the victim was shot four times, three times while on the ground.

“I remember how unremorseful Ahmad was when our family was here in court,’’ the victim’s sister, Danneka Cooper, said. “I do feel like one day he should get out, but I don’t feel like it should be anytime soon.’’

Williams apologized to the victim’s family and said he thinks about their loss every day.

“There isn’t enough words or apologies that can begin to express how truly sorry I am for what I did to them,’’ Williams said. “I’m sorry for the pain, the hurt they had to endure.’’

Kent County Circuit Court Judge Mark Trusock sentenced Willliams to between 25 and 60 years in prison. Williams, who is being held at the Muskegon Correctional Facility, will be eligible for release in less than seven years.

Family members applauded and shouted “we love you’’ as Williams was escorted out of the courtroom.

1996 Beer Kooler slaying:

Next stepped in Christopher Lee Peltier, one of three people sentenced to life in prison for the 1996 murder of a party store clerk during a robbery.

Forsyth is not blocking the eventual release of Peltier and co-defendant Saulo Montalvo because they did not fire the rounds that killed 61-year-old Rodney Corp. He is seeking a no parole sentence for the gunman, Robert Jarar Maze, who was 15 when he shot Corp.

The trio spent several days preparing for the robbery at the Beer Kooler party store on Alpine Avenue south of 9th Street NW, Forsyth said. They watched “Menace II Society,’’ a 1993 movie in which the opening scene is the robbery and murder of a liquor store clerk.

Peltier and Montalvo sawed the barrel and stock off of a long gun prior to the robbery. Because Montalvo was 16 and had a license, he served as driver. Maze and Peltier entered the store and Maze shot Corp almost immediately. Corp was shot a second time after falling to the floor.

Peltier, now 35, carried the cash register out to the waiting car. He and Montalvo, now 36, used a crow bar to open it.

Defense attorney Charles Clapp said Peltier is remorseful for what he did.

“He knows what he should have done, and that is to say ‘we’re not doing this, we shouldn’t be doing this,’’’ Clapp told the court.

Trusock sentenced Peltier to between 35 and 60 years in prison. He’ll be eligible for release in about 15 years.

Montalvo, whom Forsyth said was the least culpable of the three, made a tearful apology for his role as getaway driver.

“I am truly sorry for what I’ve done to them,’’ he said of the victim’s family. “By all rights, I should serve the rest of my life.’’

Trusock was more forgiving. The judge noted Montalvo’s exemplary conduct while in prison and the outpouring of support he’s received, including letters from the victim’s family advocating his release.

“If I had the authority to go under 25 years, I think I would,’’ the judge said.

Trusock sentenced Montalvo to between 25 and 60 years in prison. With credit for time already served, he’ll be eligible for parole in about 4-½ years.

Kentwood Fun Spot slaying:

Giovanni Casper returned before Kent County Circuit Court Judge Dennis Leiber, who presided over his murder trial nine years ago.

Casper was 17 when he fatally shot 16-year-old Kenneth Dear at Kentwood Fun Spot skating rink at 52nd Street and South Division Avenue in Kentwood. The Nov. 2006 shooting was gang-related. Casper had a gun hidden in his sleeve when he approached Dear and opened fire.

Dear, a junior at Godwin Learning Center, died at the scene.

Casper in 2009 had his conviction upheld by the Michigan Court of Appeals. Now 27, Casper is at the G. Robert Cotton Correctional Facility in Jackson.

Leiber on Friday sentenced him to serve between 40 and 60 years. He’ll be eligible for parole in a little more than three decades.