A 76-year-old Bronx man shot his 21-year-old neighbor to death after a feud that lasted for years, police and sources said.
Gilbert Smalls was arrested after he copped Friday to killing his barely drinking-age neighbor Justin Chatfield in their Morris Heights apartment building, cops and sources said.

The alleged confession came after NYPD officers knocked on the Senior Citizen’s door while canvassing for video footage in their probe into the fatal shooting Thursday, sources said.
Small ended spilling that he was the shooter, the sources revealed.
The shooting unfolded around 10:20 p.m. Thursday when cops responded to a 911 call at 30 Richman Plaza and found Chatfield with a gunshot wound to the torso, police said.
Chatfield ran back to his apartment after taking the bullet and crumbled to the floor in front of his mom Melinda, she told The Post Friday.
“‘Mom, I’ve been shot. Mom, I’ve been shot!’” he moaned, according to Melinda. “Then he collapsed on the floor.”
Chatfield lived in the same apartment building as Smalls – and the pair had been feuding for the past five years, according to cops and sources.
The victim’s mom claimed to The Post Friday that in a past frightening encounter people associated with Smalls put a gun to her son’s head.
“It was between them, it had nothing to do with me, so Justin didn’t want to press no charges,” Melinda said.
The bitter dispute between the neighbors reached its climax Thursday night, when Chatfield went to check on a commotion in the hallway, only to be blown away by Smalls, according to Melinda.

EMS rushed Chatfield to St. Barnabas Hospital, where he later died, according to authorities.
Both men had a history of run-ins with the law, according to law enforcement sources.
The elder Smalls had at least two priors – though his last arrest was over 25 years ago for assault – and he had managed to stay clean until Thursday night’s shooting, law enforcement sources said.
The junior Chatfield also had at least three recent priors, and was wanted in connection to robberies at the time of his death, law enforcement sources said.
Chatfield’s grandfather, Alan Barnwell, remembered his grandson fondly.
“He was a good kid and everything, there was nothing bad about him,” Barnwell, 75, said.
“For him to go like that, it’s so ridiculous.”