A judge ordered a Bronx man held without bail Thursday after prosecutors say he beat another man to death “without provocation” at a Brooklyn subway station, and then used the man’s credit card to buy a sword and other items.

David Mazariegos, 25, appeared in Brooklyn Criminal Court in a torn white jumpsuit to face murder, robbery and grand larceny charges for allegedly killing Bensonhurst resident Nicola Tanzi, 64, at the Jay Street–MetroTech stop in Downtown Brooklyn on Tuesday.

Sapna Kishnani of the Brooklyn district attorney’s office said Mazariegos “suddenly” punched Tanzi around 3 p.m. as Mazariegos tried to go through a security gate at the station, causing Tanzi to fall down. Mazariegos then stomped on Tanzi’s head “over and over again” until he lay limp and unconscious, she said.

Mazariegos rifled through Tanzi’s pockets, taking his credit, debit and ID cards, Kishnani said. Tanzi sustained injuries to his face and head, including a skull fracture and crushed nasal bone, she added.

The two men did not know each other before their encounter, according to prosecutors. NYPD officials said Tanzi was so badly injured that he was initially hard to identify. First responders took him to Brooklyn Methodist Hospital, where he died shortly thereafter.

“It couldn't have happened to a more gentle, kind individual,” said John Leo Heyer, a deacon who knew Tanzi from Brooklyn’s Catholic community. “Just a simple soul who went to work, did what he needed to do, came to community events, liked to be around other people, always smiled, always went out of his way, liked to tell jokes. And for such brutality, for him to be a victim of that is just the opposite of who he was as a person.”

Nicola Tanzi (center) was active in his Catholic community in Brooklyn.

Heyer said Tanzi was an usher at St. Dominic’s Church near his home, and was also active at the Church of the Sacred Hearts of Mary and Jesus and St. Stephen in Carroll Gardens, near where he grew up. His parents hailed from the town of Mola di Bari in Italy, Heyer said, and Tanzi was dedicated to keeping their traditions alive after they both passed away.

Tanzi worked as a security guard at a building near the Jay Street station and is survived by several siblings and cousins, according to Heyer.

Police said Mazariegos fled the station after the beating and got on a Bronx-bound 2 train at nearby Hoyt Street. Officers apprehended him hours later near Times Square, after law enforcement officials say he used Tanzi’s credit card to purchase a sword, herbs, socks and a hat. NYPD Commissioner Jessica Tisch said the entire force received an emergency alert to their phones with a photo and description of Mazariegos, leading officers to spot him.

Mazariegos “admitted to beating the victim, robbing him and ‘taking his spirit,’ as he put it,” Kishnani said Thursday.

Mazariegos has several other open cases in different boroughs, including an assault case in Manhattan, according to prosecutors and court records. Kishnani said several older cases against him, including a misdemeanor from 2019, were dismissed following a psychiatric evaluation. Neither prosecutors nor Mazariegos' defense attorney immediately requested a similar exam in the murder case.

Judge Philip Tisne called the allegations “the most serious charge that we have in our community.” Mazariegos’ attorney declined to comment after the proceedings. Officials said Mazariegos was living at NYCHA’s Gun Hill Houses.

The incident is the fourth homicide in New York City’s subways this year, compared to 10 during all of last year, according to NYPD reports. Official data shows this summer was the transit system’s safest summer in recent history outside of the COVID-19 pandemic, when ridership plummeted.

Heyer, the deacon, said the case underscores the need for more interventions for New Yorkers who may be struggling with mental illness.

“We need to make sure we’re protecting all people, those that are mentally ill and those that are just riding the subway,” he said. “I take the train myself everyday, and I’m constantly on the watch, and I could have been Nicky.”

This story has been updated with additional details.

Correction: This story has been updated to reflect that the incident was the fourth homicide in the city's subways so far this year.