A Bridgeport family is demanding justice for a loved one who was fatally shot in Waterbury.

The family of 40-year-old Gregory Robertson says they are angry and heartbroken three days after police say he was shot to death in Waterbury early Sunday morning.

"I'm just here demanding justice with my family. This has been very painful to deal with," said Gregory Robertson’s brother, William Robertson.

The family says they were told by detectives that Gregory Robertson was an innocent bystander struck by gunfire outside of the Bunker Social Club.

Police say 34-year-old German Pena-Lopez, of Waterbury, was arrested in connection with the shooting and that more arrests may follow.

"They need to be held accountable," said Gregory Robertson’s aunt, Felicia Robertson.

The family says the father of three sons and a daughter was born and raised in Bridgeport.

"He was all about family,” said fiancee Bianka Jennings.

The family says Robertson moved away a decade ago in search of a better life, only to get killed upon his return to Connecticut.

"To get away from violence he moves to Fredericksburg, Virginia, and comes back here to visit his son and he loses his life,” said family friend Tony Barr. "This is unacceptable. We cannot continue to allow this to play."

The family wants to advocate against gun violence in his memory in hope of saving lives.

"We can do everything in our power to try to make sure this doesn't happen again, because it's happening too often,” said his mother, Courtney Robertson.

The family says they're grateful to Waterbury police for helping them get justice. They say they want police statewide to "crack down on social clubs that act as a magnet for gun violence."