Police Troy Robinson, 29, was robbed and shot to death August 28th at a home in Wake Village, Texas.
His death is being investigated as capital murder.
Robinson's mother, LaDonna Robinson, last talked to her son the same day he was shot.
She says she doesn't know why anyone would shoot her son, but she wants justice when it comes to whoever is responsible for his death.
"They didn't have to shoot him like that. He didn't have (anything) for them to take. He didn't own his own house. All he had was him," Robinson said.
"Why did they have to kill him? That's what I want to know," said Troy's sister Trineisha Robinson.
Wake Village Police say no suspects have been arrested as of Tuesday. The investigation continues.
Police had been looking for two people of interest who may have been in contact with Robinson before his death.