LAS VEGAS (KLAS) — The father of a teen boy who was allegedly shot by a neighbor last month is questioning why the neighbor hasn’t been charged.

Christian Murphy, 16, was shot in the back of the head on the morning of April 11 in the Foothills community near Fort Apache and Flamingo roads.

Las Vegas Metro police determined the shooting was in self-defense. Police said the teen, who was armed, got into an argument with a neighbor walking his dog, who was also armed, and the two exchanged gunfire.

Christian’s father, Phillip Murphy, believes the killing was not justifiable because his son was shot from behind.

“It has been really, really tough as a father to lose your son,” he said.

Murphy is still trying to find answers as to why a neighbor pulled the trigger on his son.

“He shot my child in the back of the head so he needs to be punished for it,” Murphy said.

Murphy said Christian and his older brother got into an argument, Christian took his brother’s gun and went outside where the two continued arguing when a neighbor walking his dog got involved.

“A neighbor that lives in the next street over from where my kids grew up to try to tell them to get on the ground,” he said. “I don’t even know why he thought it was right to take in his own hands and act as a police officer.”

Murphy said both of his sons got on the ground but then his older son realized the man was not a police officer and ran back inside, leaving Christian on the ground. Seconds later, a shot was fired.

“My son had to have his back turned for him to get a bullet in the back of the head,” Murphy said.

Christian Murphy (Photo: Phillip Murphy)

Police said Christian had fired the gun he was holding before he was shot.

“There is no justifying self-defense when a bullet goes through the back of your head,” Murphy said.

Christian was taken to the hospital where doctors determined the bullet caused too much damage. His father took him off life support the following morning.

Police said the case is still under investigation and needs to go to the Clark County District Attorney’s Office for review.

“I am going to get answers I am going to fight for my son I am not done,” Murphy said.

8 News Now went to the neighbor’s home but no one in the home wanted to discuss the shooting.