Superior Court Judge Michael J. Kassel sentenced Leonce to 30 years for murder in Hawkins' death and 15 years for aggravated manslaughter in Huff's death. He must serve close to 43 years before he is eligible for parole.
Leonce and the other nine were members of the Lueders Park Piru Bloods, a loosely organized group named after the Los Angeles street gang. Hawkins was accused of being a member of the Crips, a rival street gang.
One defendant said the group believed Hawkins, of Mount Holly, had stolen liquor from the home of another defendant.
Huff, a high school senior, was killed because the defendants worried she would be a witness, prosecutors have said.
Prosecutors had sought an 80-year sentence for Leonce. His attorney, David S. Bahuriak, argued for a 30-year term, the minimum on the murder conviction, and for a concurrent sentence on the aggravated-manslaughter conviction.
"You can't quantify the need to deter this kind of crime," Assistant Prosecutor Christine Shah said, adding that Leonce was an admitted gang member with a juvenile record.
Most of all, Shah said, "there is a tremendous and overwhelming need to deter this defendant and others from threatening and harming people who have witnessed crimes."
Leonce maintained his innocence: "I didn't kill them people." But he also said he thought only about what his mother, who was not in the courtroom, thought about him.
"I don't want my mother to think she raised a monster," he said.
Prosecutors said Leonce was one of the initiators in Hawkins' assault, including beating him with a baseball bat.
Leonce also was found guilty of participating in Huff's death, including putting a bag over her head that suffocated her.
Earl Huff, Muriah's uncle, addressed the court in a fatigued but irritated tone. His mother, Sylvia, who raised Muriah, sat in a front row.
"We hear him crying about 30 years, crying about time. Muriah doesn't have any more time," Earl Huff said. "He took all her time."
Leonce also was convicted of cleaning the home of blood, disposing of the carpeting and victims' clothes, and burying the two in the backyard.
He was one of two defendants who opted to take the case to trial. The others agreed to plea deals.
Bahuriak painted his client as a juvenile swayed by older gang members. Leonce was raised by an older brother who was incarcerated, he said.
At one point, he turned to the spectators and asked whether there was anyone from Leonce's family in the courtroom. No one answered.
"There was nobody here during the trial," Bahuriak said. "It speaks to the kind of upbringing Mr. Leonce had endured."
Contact Darran Simon at 856-779-3829, firstname.lastname@example.org, or follow on Twitter @darransimon.