The Bronx psycho suspected of beating a man to death because the victim held a subway exit door open for him was out on the streets despite allegedly carrying out an eerily similar attack on a security guard – who counts himself lucky to be alive.
The security guard, who asked to be unnamed, exclusively told The Post Wednesday he could tell the suspected killer — identified by sources as David Mazariego, 25 — was a “very dangerous person” during their June run-in outside a Chelsea theater.
He said the unhinged stranger sucker punched his glasses off his face after he tried to shoo the maniac from an event for troubled kids.
“I told the prosecutor, I said, this guy is gonna do this again, you better take him off the street before he does this to someone else,” the guard said.
“Obviously, I was right,” he added. “It could have been me, you know.”
Mazariego was in custody after cops arrested him with a sword in Times Square Tuesday evening — hours after he allegedly pummeled a still-unidentified man to death outside Brooklyn’s Jay Street-MetroTech station.
He was out on $1,000 bail in the violent assault in Manhattan when he allegedly carried out the brutal beating in Brooklyn, online records show.
Law-enforcement sources said Mazariego has a lengthy rap sheet that also includes arrests for minor offenses such as fare evasion, graffiti and criminal mischief, in addition to the violent attack over the summer.
The assault unfolded late June 24 after Mazariego kicked the glass entrance door to a West 23rd Street theater open, sources and the security guard said.
“Luckily, the glass doors didn’t break, but I stepped outside and before I knew it, he just hit me,” the guard said.
“You don’t need to have a PhD in psychology. You just look at this guy and can tell he’s trouble.”
State court officials and the Manhattan District Attorney’s Office didn’t answer questions about the June case.
Mazariego’s defense attorney in that case didn’t return a call for comment.
