COMMERCE CITY, Colo. -- The family of a man gunned down inside his store one week ago made an emotional appeal Thursday for anyone who knows about the shooting to come forward.

Commerce City Police are still trying to figure out who shot Dung Le at the Dollar Value Plus store and why.

"I thought it was just like a nightmare," said Le's wife, Dao Vo.

Le, 39, was a husband-father-and son who was killed inside the Dollar Value Plus store he worked so hard to keep. He worked seven days a week, trying to support his family.

His brother-in-law, Kevin Le, called him a generous man -- someone who practically gave things away -- only to have his life stolen.

"Things just happened so quick, suddenly. He's gone, so right now our family is just devastated," Kevin Le said.

His family said Le was so generous and understanding that he would let customer take the groceries without paying if he knew they couldn't afford it.

Police said they have many pieces to the puzzle, but the picture of what happened isn't clear.

"As we put those pieces of the puzzle together. They are not matching up or making sense to us right now," Commerce City Detective Mike Saunders said. "We need other pieces of the puzzle to fill gaps."

Le's family's went public Thursday, begging for help in finding the killer.

"Please come forward. Your voice means a lot to our family and the community," Kevin Le said.

Dung Le lost his job as a design engineer several months ago and was struggling to keep the store afloat.

Police are still looking for a white van seen in the parking lot of the store between 11:30 a.m. and 1 p.m. on the day of the shooting. It was facing the store, located at East 63rd Place and Ivy Street.

Commerce City police hope someone in the van saw something that could help their investigation.

If you have any information that could lead to an arrest, you could receive a $1,500 reward.