UPDATE:Troy Ave has been arrested following the shooting that took place at Irving Plaza on May 25. According to ABC7 News, he has been charged with attempted murder and two counts of criminal possession of a weapon, though the NYPD reports that he may face additional charges.

The arrest follows the discovery of video footage that shows the rapper—real name Roland Collins—firing a gun inside the venue. Police are not yet sure if another shooter was involved. An investigation is still underway.

It is also believed that Collins' leg injury was self-inflicted and likely an accident.

T.I., who was set to perform the evening of the shooting and who was not injured in the attack, has finally acknowledged the incident on Twitter, sharing this emotional message with his followers:

ORIGINAL POST (MAY 26): One person was killed and three others were wounded during a shooting at Irving Plaza in New York City late Wednesday evening (May 25). The incident took place shortly after 10 p.m. inside the venue located near Union Square, where rapper T.I. was set to perform.

According to NYPD officials, the shooting was related to a fight that took place backstage in a green room located above the stage area. The NY Daily News reports that "the carnage started as a beef between two rival crews associated with Maino and rapper Troy Ave," the opening acts for T.I. The "DOPE" rapper was not onstage at the time of shooting, though he's said to have been in the building. Rappers Maino and Uncle Murda were performing when the incident occurred.

NBC News (New York) reports that the victims include three men, one of whom died after sustaining a gunshot wound to the stomach, and one woman. One of the male victims who was shot in the leg is reportedly Troy Ave. Another, who was shot in the chest, remains in critical condition.

Police confirmed that metal detectors had been set up at the venue. However, witnesses claim that security procedures entering Irving Plaza were lax overall.

No arrests have been reported as of yet, and it's still unclear what prompted the shooting.