More details have emerged about the 21-year-old man who was fatally stabbed in the neck in a tenement on East 7th Street yesterday morning. Police say Christopher Jusko's assailant was 25-year-old Jairo Pastoressa, who resides in the building. One source tells the Post that the two men were in an argument over Jusko's ex-girlfriend, who also lives at the address. Pastoressa, 25, confronted Jusko around 5:30 a.m. and then plunged a knife into his neck.

Sources tell the Journal (paywall) that Jusko had called his ex on the phone and the two got into an argument that escalated when Jusko went to the building. He was arguing with her in the hall when Pastoressa emerged and allegedly stabbed him in the neck and back. He turned himself in yesterday and claims he stabbed Jusko only after he brandished a gun, but police say no gun was found at the scene.

Jusko staggered out to the street, and was found dead in a pool of blood outside the building. Pastoressa is currently in the psychiatric ward of Bellevue Hospital, and his neighbors tell DNAinfo they're surprised that the "laid back" graffiti artist is accused of murder. Another neighbor called Jusko a "loudmouth," adding, "he was not all there."