It all happened at the Reginelli's Pizzeria at Bissonnet near Bellaire around 9:30pm.
Police say the victim was an employee who was closing the front of the store while the other workers were in the back office.
Eyewitness News has learned his name is Peter Mielke. His mother tells Eyewitness News he played high school football and was a sophomore in college. He was working to pay for college. Mielke's mother tells us he never asked for money and wanted to do his own thing. The teen's mom said he had a lot of friends and was an overall great kid.
"He's missed by a lot of people. He had a lot of friends cause of his attitude. He was never a down person. He was the fun one. You always wanted to be around him. He was just a joy. He was a good kid," said Dana Mielke, Peter's mother.
The gunman stormed in and demanded money. Moments later the teen was shot.
The police chief calls the killing senseless.
Bellaire Police Chief Byron Holloway said, "We're not sure why he shot the victim. The victim was cooperating with demands he was giving."
No customers were inside the restaurant when it happened. Investigators don't believe the suspect got away with any cash. He did, however, take Dana Mielke's son's life.
"I'm going to pray for you all. You took my son, I'm still going to pray for you," said Dana Mielke.
"A very senseless shooting over a robbery. Probably a small amount of cash is all they have on hand. We are hoping to find some more information about what happened," Holloway said.
Investigators are now going over surveillance video to see if there's a good look at the suspect and to piece together what happened.
Co-workers and friends of the teen are trying to wrap their minds around what happened.
"We were a crew, we were family with one another. None of us harmed anyone. None of us. We all stayed away from all that. We all veered away from that path," said Tyler Ramsey, who used to work at Reginelli's with the teen killed.
Ramsey said his friend was one of the restaurant's best servers. Restaurant owner, Darryl Reginelli, tells Eyewitness News the teen worked at the pizzeria for years.
"He didn't deserve this. He didn't do anything to anyone that would deserve this. He's not that kind of person," Ramsey said.
Darryl Reginelli, the restaurant owner, flew in from New Orleans Monday morning to assist police as they investigate.
He too talked about how loving and kind Peter was.
"Just a really positive attitude and loved to talk and greet people and say hello. He was very engaging," said Regineilli.
Reginelli closed the restaurant so that employees could grieve. People dropped by to leave flowers out front for Peter.
Regeinelli has opened an account for Peter. You can donate to the Peter Meilke Memorial Fund at any Amergy Bank. In addition, a GoFundeMe page has been set up.