With a new Netflix documentary bringing renewed attention on the case of Sean Ellis, Suffolk County District Attorney Rachael Rollins says she plans to re-examine the case. “This is not the last time you'll hear me speaking about Sean Ellis,” Rollins said on Greater Boston Monday, “And I'm confident that won't be the last you hear from this office about what it is he's done or who it is he will hopefully become.”

Ellis was convicted in 1995 for the murder of Boston Police Detective John Mulligan, two years and two hung juries after Mulligan’s death outside of a Wallgreens in Roslindale. Ellis spent 22 years behind bars, serving a life sentence, until a Boston judge ruled that “justice was not done” and overturned the conviction. Ellis was released in 2018.

After the Netflix documentary "Trial 4" shed new light on the case, Ellis’ defense attorney, Rosemary Scapicchio, called on Rollins to fully exonerate Ellis.

“I think she could. I don't know if she will, but I think she could, based on all of the evidence that's been developed in this case,” Scapiccio told GBH News earlier this month. “[Rollins could] give Sean the opportunity to not be a convicted felon, to go and live the rest of his life as the person that he is, and not drag that ball and chain around with him on this gun conviction.”

In Ellis’ first trial, the then-19-year-old Black man was accused of possession of a firearm, but the trial resulted in a hung jury and a mistrial. The second trial resulted in the same thing, because the jury was unable to reach a unanimous verdict. Ellis was convicted of armed robbery and first-degree murder, and then a judge granted a motion for a new trial. “Whatever will be filed with us, we will consider whether there is a motion for a new trial on the gun,” Rollins said.

At the time of his death, Mulligan was being investigated for both internal policy violations and crimes including the armed robbery of a suspected drug dealer. A 1996 report by the Boston Globe’s Spotlight team revealed that Mulligan’s colleagues, Detectives Kenneth Acerra, Walter Robinson, and John Brazil were involved in corruption schemes including falsifying search warrants, demanding bribes including money and drugs, and extorting additional payments by not showing up to scheduled court appearances. Acerra’s girlfriend’s niece, Rosa Sanchez, also served as a key witness during Ellis’ trial.

“This case has a lot of very glaring constitutional violations that have occurred.” Rollins said. “We need to look at some of these officers that were dirty, quite frankly, and see what other cases they might have touched.”