A 15-year-old boy died and a 14-year-old is possibly paralyzed after apparently trying to steal marijuana plants from a Denver backyard.

The man arrested for shooting the teens is facing first-degree murder and attempted first-degree murder charges. The Denver District Attorney's Office has not yet officially charged 48-year-old Keith Hammock and he remains in jail.

Early Sunday morning, a 14-year-old called 911 saying he and his friend were shot.

Denver Police found the teens in the backyard of a house near 28th and High Streets after using Shot Spotter to find them. Shot Spotter is the gunshot detection technology used around the city.

Keylin Mosley, 15, died of a gunshot wound. His picture and candles are placed in the alley near the backyard.

According to arrest documents, the teens were found in the yard containing marijuana plants. Some of the plants were being grown inside orange 5-gallon buckets. Police found pot leaves in the alleyway and one of the buckets with a plant in a neighboring backyard.

Police spoke with Hammock and his female roommate who live in the house on the property. Hammock told police he heard an argument and then gunshots. He said someone jumped over his fence and activated the motion detector light. That's when he went downstairs and saw two kids laying on the ground.

But after serving a search warrant, police went to the second floor bedroom overlooking the backyard and found two long rifles, ammunition and four spent cartridge casings, two of which were on the window sill.

"You can't shoot somebody on the porch, you can't shoot somebody in the driveway and you sure can't shoot somebody who's stealing marijuana plants from your backyard," said 9NEWS Legal Analyst Scott Robinson.

Robinson said Colorado's Make My Day law cannot be used as a defense. It only applies inside the four walls of a home if an intruder intends to commit a crime and poses a risk of violence to someone inside.

"The law is very clear. You can't use deadly force in defense of property, ever," he said.

Police did find a gun near the teens but haven't determined whose gun it is.

"If in fact the handgun found in the yard can be tied to one of the two young men, then and only then is the a possibility of a self-defense argument. Problem is, that neither occupant of the home described an event that would have justified the use of deadly force in self-defense," said Robinson.

When police contacted the mother of the 14-year-old, she said her son told her he was shot for the second time while he was climbing over the fence. She said her son's injuries may cause him to be paralyzed from the waist down.