Mercer County prosecutors say the shooting happened around 6 a.m. at Priori's Delicatessen on the 300 block of Hillcrest Avenue.
Investigators say an unidentified gunman came into the store and shot 54-year-old Oscar Palacios and his brother Jose.
Oscar died from his injuries. Jose remains in the hospital.
Authorities say neither brother was armed.
Family members say Oscar had been working at the deli for 22 years and was proud to have taken it over only a few months ago.
"No matter if you have money, you don't have money, you can come to the deli," said Antonio Palacios, the victims' other brother.
"He didn't have problems with nobody. My brothers, they're good. I don't know who did that. My brother never do nothing bad to nobody," said Antonio.
Family, neighbors, and police say the deli was popular. Officers would often get lunch here too.
"I feel like, like I lost a part of the community, not just breakfast and lunch, but they were great people to talk to," said Dario Panfili, owner of Dario's Imported Car Service which is next door to the deli.
Police say they are investigating a motive and no arrests have been made.
Neighbors are shocked this kind of violence came to their block.
"It's very scary. In fact, my wife has been pushing me to retire. I think this is time," said Panfili.
"Never had a problem down there. Never. This is breaking news to everybody around here, ya know? This is very sad," said Jerome Inman, a neighbor.
Inman says he will miss his friend Oscar who always made sure the neighborhood was fed.
"He just treated everybody very specially. He was one of the best persons you ever wanted to meet. Just outstanding," said Inman.
The Palacios family says they visited Jose in the hospital and they were able to talk to him.
Anyone with information is asked to contact the Mercer County Homicide Task Force at (609) 989- 6406.