A federal agent fatally shot his girlfriend, a nurse, in the Bronx before calling her father and stating "she's gone, Rudy" – his final words before turning the gun on himself, according to the victim's father.

Rudy Cantarini, a retired NYPD officer, recounted the harrowing events of Tuesday night, stating his 37-year-old daughter, Andrea Cantarini, had called him at 8:47 p.m. "begging for her life." She remained on the phone with her father while her boyfriend, Juan Cornelio Diaz, 38, allegedly shot her in the head inside her Riverdale apartment.

Diaz, who was identified as a U.S. Customs and Border Patrol Officer stationed at JFK airport, was found at the scene with a self-inflicted gunshot wound to the head.

"I have to live with this the rest of my life, and she was the apple of eye," Rudy Cantarini told The Post. "She just didn’t want to be in a relationship with the guy anymore, and he couldn’t take it, so he did the cowards thing, and he killed her and himself."

U.S. Customs and Border Patrol Officer Juan Cornelio Diaz stands with Rudy Cantarini outside outdoors.

Andrea Cantarini smiling in a blue blazer.