CYPRESS, Texas -

A family is devastated after a neighbor shot and killed their dog, a Boxer named Gunner.  

"He pulled out a gun and shot him in the neck at point blank range," said Kevin Fitzhenry, the dog's owner. 

Fitzhenry said the dog got out of their fenced-in backyard when his sons went to retrieve a ball that had gone over the fence. 

Walking along a nearby trail was their neighbor, Mark Condon who is an off-duty Houston police officer, Condon's wife and their two dogs.

Fitzhenry's 12-year-old son, Dalton, said he witnessed the entire incident. He admitted the dog got out, wasn't on a leash and was barking at the other dogs, but said he was right there to get him. 

"I was standing there calling him as he got shot," Dalton Fitzhenry said. 

"I can't get over the kids screaming, I can't get over my wife screaming, it's all I hear now," said Dalton's dad. 

Local 2 stopped by Condon's home several times but no one would answer the door. 

In an emailed statement, Condon said, "The dog charged us and attacked me, my wife and one of our dogs. All three of us sustained injuries from the attack, which were documented by the Precinct 4 Constable's Office. I felt that I had no choice but to shoot the other dog to stop the attack."

Officers with Precinct 4 Harris County Constable's Office are investigating the incident.

A chief in the department told Local 2 they are still interviewing witnesses and gathering information. The chief explained that the stories from the family and the off-duty officer are very different. 

The Fitzhenry's are hoping someone will learn a lesson from their loss. 

"Never would I have thought he would have been shot basically because he was going to retrieve a ball with his owner," said Fitzhenry. "You have to keep your dogs on a leash."