"I heard what sounded like explosions in the far distance. I don't know, I thought maybe someone had set off some fireworks or something. I sure didn't think gunshots at the time," next door neighbor Fred Schwartz said.
Police responded to the family's home on Sunflower Circle at 10:15 p.m. Monday after receiving a request for a wellness check from a relative.
Officers didn't know what to expect and asked neighbors to take shelter.
"[Police] said you should move to the other side of the house because there was the possibility of gunfire," Schwartz said.
Inside the home, officers discovered the bodies of 50-year-old Ruben Johnson Jr., his wife, 48-year-old Mishanda, and their 10-year-old son, affectionately known as "Tre."
The Burlington County Prosecutor's Office says their investigation revealed that Ruben Johnson Jr. fatally shot his wife and their son before turning the gun on himself.
The couple's daughter, LoraVon Johnson, was away at college in Florida at the time of the murders.
"I heard the news. I'm just in shock. I can't believe it. It's very sad and disturbing," said Schwartz.
There is no known motive yet.
"You always want to be cordial and be a good neighbor. But I guess you never know what's behind the walls," said neighbor Kelly Feoli.
Authorities say no other suspects were involved in the shooting.