Two North Charleston residents will spend less than 15 years in prison after admitting to roles in a fatal shooting two years ago in which investigators struggled with uncooperative witnesses.

Demetrius Robinson, 18, was slain May 31, 2012, at an apartment complex on Delta Street. Jonathan Thompson also was wounded.

But Thompson and another eyewitness resisted prosecutors' attempts to get them to testify, Assistant 9th Circuit Solicitor Culver Kidd said Tuesday.

That's why Kidd said he negotiated sentences for the two defendants as part of plea deals on lesser charges.

Maurice Nathaniel Aiken, 27, of Taylor Street, who had faced a murder count, was sentenced to 15 years in prison for voluntary manslaughter. The charge was punishable with between two and 30 years.

Aiken will not be eligible for parole, so he must serve at least 85 percent of the time. Judge Roger Young approved the sentence April 29.

Michael Arkeilo Montez Nelson, 28, of Dorchester Road pleaded guilty Monday to being an accessory after a murder. Judge Deadra Jefferson signed an order sentencing him to 11 years. He will be eligible for parole.

Aiken was given credit for the nearly two years he served in jail while awaiting trial. The North Charleston Police Department arrested him on the day of the killing.

Nelson was arrested a week later.

Both men also had faced a charge of attempted murder in Thompson's wounding. But Thompson, who was hit in the shoulder, refused to testify against them, Kidd said.

"Whenever law enforcement did speak with him," Kidd said, "he maintained the position that he didn't know anything."

In parts of North Charleston and Charleston where crime is frequent and the illegal drug trade is prevalent, detectives often encounter problems with victims and witnesses who abide by an unwritten "no-snitching" code on the streets.

Both men had lengthy criminal histories that included convictions for drug possession. Aiken's rap sheet, which was the most extensive, featured convictions for trafficking cocaine and assaulting an employee at Stall High School, which he once attended.

Last year, Aiken rejected a plea offer before a scheduled trial.

His first trial date came in early August. But after a jury was selected, prosecutors learned that a key witness was refusing to show up. The mother of Aiken's child, who Kidd said could testify about a motive in the shooting, was arrested for disobeying a subpoena. The trial was postponed.

She later was fitted with a Global Positioning System monitoring device and ordered to stay at home. But she broke those conditions, court documents stated. Prosecutors feared that she would continue to avoid taking the witness stand.

A man who had identified Aiken as the gunman also refused to testify, Kidd said.

"Our two witnesses that put Aiken on scene as the shooter have both either recanted their statements or were flat out refusing to testify," Kidd said.

In Nelson's case, his car was used to transport Aiken to and from the shooting scene in the Russelldale neighborhood, Kidd said.

But that was the only evidence against him, and Kidd said it didn't show that Nelson knew about a planned crime before it happened and otherwise had a greater hand in the shooting.

Police investigators, Kidd said, "were keenly aware of our predicament and supportive of the resolution that we obtained."

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.