HILLSBOROUGH - Authorities haven't charged the man they think was the actual shooter, but they achieved a prison sentence Monday for one of three men alleged to have helped kill a woman at her Cedar Grove home.

Reshaun Cates, 22, pleaded guilty to second-degree murder and armed robbery in the shooting death of Eva Jacobs two years ago. Cates will serve 12 to 16 years in prison after District Attorney Jim Woodall dropped a first-degree murder charge.

In a direct letter to Superior Court Judge Carl Fox a year ago, Cates circumvented his attorney, Public Defender James Williams, and demanded a speedy trial, saying he was innocent. Woodall was surprised by Cates' guilty plea, a day after the district attorney spent two hours interviewing a key witness who only recently agreed to testify that Cates confessed the crime to him.

Woodall said there was no question Cates was involved, but the prosecution depended on linking a white, extended-cab Ford F-150 pickup truck containing Cates' fingerprint to a tire tread left in Jacobs' driveway. Williams was fighting to keep a tire-tread expert from testifying for the state, and Woodall struggled for two years to persuade Cates' fellow gang members to testify against him.

"Everybody involved in this had been in a gang together in Durham," Woodall said. "There's a code of silence."

In court Monday, Woodall said he thinks Cates' friend Montez Stevons was the shooter and that another youth, Done Johnson, was also involved, but he lacks the physical evidence and witnesses' testimony that he has against Cates. So far, no witnesses have come forward with the same incriminating statements from Stevons or Johnson that Cates made.

"In essence, Reshaun Cates got charged and convicted because he talked to a person who was willing to come forward," Woodall said in an interview. "The hope is that someone will come forward, just like someone came forward with Reshaun Cates. ... There's always a potential for more charges. I don't think it's likely."

From what Jacobs told authorities as she was dying and what witnesses have said, Orange County sheriff's investigators concluded the suspects knew Jacobs' son, Gabe, and came looking for a supply of marijuana the family had for sale. Woodall said the men intended to rob Jacobs but not to kill her. Woodall said Stevons shot her two protective dogs and expected her to submit to the robbery.

The lanky Cates appeared in court Monday in an orange jumpsuit and bushy beard. He will be in his mid-30s when released.

"He's actually one of the most engaging people that I've had the opportunity to represent," Williams told the court. "This young man has a lot of potential. He has the support of family. ... I think he has the potential to come out of prison and do positive things in the community."