A former friend and fellow inmate of accused killer Marcellus Jones told a Philadelphia jury Friday that while both were housed at Graterford Prison in 2009, Jones admitted killing teacher Beau Zabel.

"It got ugly," Devonne Brinson said Jones told him about the early morning robbery on June 15, 2008, that ended with the death of the 23-year-old Zabel.

Brinson told the Common Pleas Court jury that Jones also acknowledged shooting and killing Tyrek Taylor, his alleged accomplice in the robbery.

"He was weak. He would probably snitch," Jones said, according to Brinson.

The chance meeting, which occurred between Sept. 8 and Oct. 5, when both men were housed on E Block, A Section, of the prison in Montgomery County, was a reunion of sorts.

Brinson, 33, said he and Jones grew up together and were part of a group of young men who claimed the 1300 block of Colorado Street in South Philadelphia as their own.

In 2009, Brinson was more than a year into a five- to 10-year sentence for being arrested with a gun, which violated his conviction for gun possession in a 2003 shooting. Jones had just been arrested in the Sept. 6, 2008, slaying of Taylor, 19, who was gunned down outside his South Philadelphia house less than three months after Zabel was killed.

And unknown to Jones, Brinson was now in a far different frame of mind.

Brinson said his South Philadelphia associates had promised that while he was behind bars, they would take care of his infant daughter and hire a top lawyer to get him out.

But after he argued about a woman with another imprisoned pal, his support network dried up, Brinson said. There was no money for his daughter or his other two children, and no lawyer to represent him.

"I put all my life in the streets, and got nothing in return . . . no loyalty," Brinson told the jury.

Also unknown to Jones was that months earlier, Brinson said, he got a call on his contraband cellphone from a very panicked Taylor. Brinson said Taylor wanted to talk to Taylor's brother Michael Wynn, who was imprisoned in a cell near Brinson's.

But before he passed the message to Wynn, Brinson said, he managed to wheedle out of Taylor why the call was urgent: Taylor said he and Jones had gone out to rob someone, and Jones shot and killed "the teacher."

By the end of October, Brinson penned a note to prosecutors saying he could give information about three murders, including those of Zabel and Taylor. On Nov. 4, 2009, he gave a statement to Philadelphia homicide detectives.

Questioned by Assistant District Attorney Tracie Gaydos, Brinson said he decided to contact authorities because he hoped to collect the $20,000 reward for the arrest and conviction of Zabel's killer.

"I thought at least the reward could support my daughter," he testified.

Brinson, dressed in jeans and a black T-shirt with the words "I Am Philly" in gold letters, spent two hours being questioned by defense attorney Richard J. Giuliani.

Giuliani went through transcript after transcript of Brinson's criminal cases to try to paint a portrait of a self-aggrandizing career criminal who did not hesitate to lie under oath.

In a transcript of a prior closed-door hearing in a 2011 trial before Judge Rose Marie DeFino-Nastasi - the same judge as in the current Jones trial - Brinson refused to testify about the murder of a friend, saying he feared for his family's safety.

When DeFino-Nastasi told Brinson he had to testify under oath or she would hold him in contempt of court, Brinson replied, "Who do you think you're talking to, your dime-store thug?"

Brinson sheepishly admitted that that was what he said, and added later that he apologized to the judge and testified in the trial. Brinson said that at the time, he was upset because his youngest brother had been murdered in South Philadelphia just three months earlier.

Giuliani also repeatedly questioned Brinson about his testimony, asking whether Brinson had a deal with prosecutors or an expectation that he would get a reduced sentence. Brinson said he had no deal.

But then Giuliani noted that Brinson was free after his sentence for the probation violation was reduced in 2014 from the original five to 10 years to basically time served.

Friday marked the fourth day of testimony in the trial of Jones, 37, in the slaying of Zabel, a Drexel University teaching fellow who had been in the city just six weeks from Austin, Minn., when he was killed in a robbery that netted the shooter an iPod.

Brinson also testified against Jones in 2012 in Jones' trial in Taylor's slaying. Jones was found guilty of first-degree murder and sentenced to life in prison without parole.

A year later, after further investigation by a grand jury, Jones was arrested and charged with Zabel's murder.

Prosecutors have acknowledged that no DNA or other physical evidence will link Jones to Zabel's slaying. Instead, prosecutors say, Jones incriminated himself through his admissions to Brinson and friends and relatives that he was the one who shot Zabel in the back of the neck.

jslobodzian@phillynews.com 215-854-2985 @joeslobo