The Brooklyn DA has decided not to prosecute the retired Correction Officer who fatally shot a man in the Borough Hall subway station in March. Video of the fatal encounter on the station's mezzanine showed William J. Groomes, 69, scuffling with the victim, a construction worker named Gilbert Drogheo, 32, moments before a single shot was fired from Groomes's gun.

The incident started on a Brookyn-bound 4 train minutes earlier, apparently after Groomes walked between Drogheo and his friend, Joscelyn Evering, 28. Words were exchanged, and the altercation became physical, spilling out into the Borough Hall subway station. Another segment of video depicts a bystander yelling to Groomes not to shoot anyone as he descends a staircase; moments later he came back upstairs and shot Drogheo.

Groomes was not arrested immediately after the shooting, but Evering, 28, was charged with aggravated assault, harassment, and menacing, and prosecutors are moving forward with that case. But yesterday, Brooklyn DA Ken Thompson said there was not enough evidence to prosecute Groomes, having "determined that criminal charges are not warranted in this matter." In a statement, Thompson said:

"Based on interviews of multiple eyewitnesses to the events leading up to the shooting, our review of video tapes of the shooting itself and other evidence, I have decided not to put this case into the grand jury and will not bring criminal charges against Mr. Groomes. While the death of this young man was indeed tragic, we cannot prove any charge of homicide beyond a reasonable doubt."

In the days following the fatal shooting, Norman Seabrook, head of the correction officers' union, said that Groomes was "remorseful" about the shooting but insisted that he had been protecting himself and had "done nothing wrong."

During a phone interview this morning, Drogheo's mother Linda Rodriguez said, "I don't understand how you say there wasn't a crime committed, when this is on video. This is horrible." Asked about the Brooklyn DA's decision, a distraught Rodriguez told us she wants to ask Thompson, "How much of a horrible man can you be? How blind can you be? I don't understand how you say there's no crime committed? You see this man coming up the stairs, hitting my son, and shooting him!"

Rodriguez says she plans to sue the city. "I just want justice for my son," she said. "I want us to go to court. I need help, I want someone to help me, to fight this. I'm not going to give up... And they wonder why everyone feels the way they do about the cops. There's no justice, they're going around and just killing people because they have a badge."

Reached by phone, Evering's mother, Paula Livingston, was incredulous. "I think it's the most ridiculous think I've ever heard of, because what more evidence did you need in the video?" Livingston wonders. "This thing about it was 'self-defense'—there was no self-defense because the boy didn't have any weapons on him, and he wasn't fighting back."

Livingston also says witnesses observed Groomes loading his gun on the train. "This means he intended to shoot someone and it cannot be a citizen's arrest," Livingston says. "No citizen is allowed to chase people down and shoot them. I'm just appalled at how our judicial system works, and it's just terrible."

M.J. Williams, an attorney who works with the protest group NYC Shut It Down, has been organizing demonstrations to raise awareness about Drogheo's murder. This morning Williams issued this statement on behalf of the group:

"We are appalled and deeply concerned by DA Ken Thompson's decision not to prosecute Will Groomes for any crime. The eyewitness videos taken on March 10th show Groomes roaming a crowded subway station during rush hour with a loaded gun pursuing Drogeho, capturing, hitting then shooting him at close range. According to the Brooklyn DA, that is not criminal. Or maybe that is not criminal if you are a former law enforcement officer. This case casts much doubt on DA Ken Thompson's ability—and any District Attorney's ability—to prosecute law enforcement officers whether on duty, off duty or retired."