The Philadelphia District Attorney’s Office on Friday said it would not seek to retry the accused gunman in the 1990 murder of a North Philadelphia businessman, two years after prosecutors dropped charges against the defendant’s brother in the killing.

The decision, announced during a brief hearing at the Stout Center for Criminal Justice, essentially marks the end of a slow collapse of the case against Mustafa Thomas and his brother, Shaurn. Each was previously sentenced to life in prison for alleged roles in the robbery and fatal shooting of Domingo Martinez.

Shaurn Thomas was released from prison in 2017 and ultimately cleared after prosecutors said potentially exculpatory evidence had been found in a long-missing police file.

On Friday, Assistant District Attorney Ashley Martin said prosecutors would not pursue a retrial for Mustafa Thomas, 52, because they did not have enough evidence to convict him again. He had been granted a new trial last year when Common Pleas Court Judge Rose Marie DeFino-Nastasi ruled that evidence potentially helpful to his defense — including statements that could have pointed to another suspect — were not turned over by prosecutors before his 1995 trial.

Friday’s decision clears Mustafa Thomas of involvement in Martinez’s killing, but does not pave the way for him to be released from prison. He is serving another life sentence in an unrelated 1990 murder, according to court records.

It also was not clear whether District Attorney Larry Krasner’s office believed in Thomas’ innocence in the Martinez case. Martin did not offer an opinion during her appearance before Common Pleas Court Judge J. Scott O’Keefe, and she declined to comment afterward.

Still, Shaurn Thomas, who attended Friday’s proceedings, said that his brother “didn’t do this murder,” and that he believed it was important for charges to be dropped even if his brother is behind bars for another killing.

“Justice is justice,” Shaurn Thomas said. “Now we can close that chapter and move on.”

No one from Martinez’s family was in the courtroom Friday. Martin told the judge that prosecutors had spoken with his daughter, who “does not wish to be involved in the process any further.”

Mustafa Thomas had been accused of fatally shooting the 78-year-old Martinez on Nov. 13, 1990, after Martinez, who owned several North Philadelphia travel agencies, had withdrawn $25,000 from a bank.

Prosecutors said at trial that Thomas, his brother, and several others were part of a gang that committed robberies in the neighborhood. On the day of the killing, they said, Mustafa Thomas rammed a car into Martinez’s on the 800 block of West Sedgely Avenue, then fired a shot into Martinez’s chest and stole the cash.

The prosecution rested largely on the testimony of two alleged coconspirators also charged in the crime, according to court documents: brothers William and John Stallworth. Each agreed to plead guilty to charges that led to sentences of fewer than 20 years.

But last year, DeFino-Nastasi, the judge who overturned Thomas’ conviction, said the Stallworths were “corrupt and polluted sources who received a very good deal for their testimony,” according to court transcripts. DeFino-Nastasi also ruled that incriminating evidence against the Stallworths was not turned over to Thomas’ attorneys before trial.

In addition, Shaurn Thomas’ appellate attorney, James Figorski, said the Stallworths had recanted their statements and claimed that detectives working the case coerced them into providing false information.

Shaurn Thomas was freed in 2017 because prosecutors with the district attorney’s conviction review unit — which at the time had been criticized for a lack of production — found a long-missing police file containing information about another potential suspect, Oliver Walthour. Prosecutors said that information was never turned over to defense lawyers.

DeFino-Nastasi said the information about Walthour was also never turned over to Mustafa Thomas’ lawyers. And according to the judge, the documents said that Walthour was stopped by police days after the homicide in a damaged car that matched a witness’ description of the vehicle used in the Martinez killing; that he told police otherwise unknown details about the murder while seeking to point the finger at someone else; and that when police asked him to take a lie-detector test, he declined and said he had been lying to them.

In addition, months after the Martinez killing, Walthour was charged with fatally shooting another Latino store owner just blocks from where Martinez was slain.

But none of that information was turned over to Thomas’ attorneys before trial, court documents say. DeFino-Nastasi said: “All of that information … would have been really, really important information to the defense. It would have totally signaled to the defense that there was something … very, very important that they needed to investigate.”

Walthour is serving a life sentence for the March 1991 slaying of store owner Rene Cardona, court documents say.

Mustafa Thomas’ appellate attorney, James Berardinelli, said after Friday’s hearing that a “great deal of evidence” cast doubt on his client’s involvement in Martinez’s slaying, and that “we’re obviously pleased” prosecutors decided against taking the case before a jury again.

Figorski, Shaurn Thomas’ attorney, said Friday that he did not think either Thomas brother was involved in the killing, and that as a result, the real shooter had been allowed to escape justice.

“Don’t you want to get the right person for that?” he asked.