"I ran out and I flagged down [an] officer," said Flores, who lives on 100 block of North 24th Street.
Authorities said that Narvaez-Betancourt, 32, who lives next to Flores, and Garcia, 22, of the 2700 block of Federal Street, were fatally shot in Narvaez-Betancourt's home around 11:17 p.m.
A 28-year-old man, who also lived in the home, was seriously injured and was being treated at Cooper University Hospital in Camden.
The shootings was part a violent Saturday night in the city. Within an hour, three people were shot, one was fatally stabbed, and one was killed in a hit-and-run. The three incidents are unrelated police said.
Around 10:35 p.m., Bruce Matthews, 31, of the 1300 block of Chase Street, was found stabbed to death near the intersection of Louis and Everett Streets. Matthews, who suffered multiple wounds, was injured in an earlier stabbing on Feb. 2, law enforcement sources said.
Around 11 p.m., Edwin Cardona, of the 900 block of 20th Street, was hit by a car at Biederman Avenue and River Roads, authorities said. No description of the vehicle was available. He died at the scene, police said.
Authorities have released few details in the double-homicide.
Narvaez-Betancourt's mother rented rooms in the house and Narvaez-Betancourt lived in the basement, Flores said. And as many as 10 people were living there, he said.
Flores said Narvaez-Betancourt planned to visit his young son back in his home country of Nicaragua in the next month or two.
He worked construction jobs and as a gardener, and often offered to help neighbors on their gardening and construction projects, Flores said.
"He's going to be missed," Flores said.
Authorities are seeking help in all of the incidents. Anyone with information should contact the Camden County Prosecutor's Office at 856-225-8400 or the Camden police at 856-757-7420.
Contact Darran Simon at 856-779-3829 or firstname.lastname@example.org or follow on Twitter @darransimon.