LAS VEGAS (KSNV) — A North Valley family is demanding justice after they say their neighbor shot and killed their dog.

Court records show police arrested 31-year-old Sergio Ramirez on Wednesday.

pause sound of gunshot, dog barking (cut video before dog takes off)

It's a horrific incident that Gerard Centelles never thought his family would experience.

He caught this video on his surveillance camera of his dog, Simba, who he says can be seen being shot by someone Centelles identified as a neighbor across the street.

The neighborhood is near the 95 and Gowan.

Centelles says he has no idea why it happened.

"No, I don't know, honestly. Like I said, I know Simba was out. As you can see in the video, he was just outside. He wasn't even barking. He didn't charge anybody. He was just standing there," he said.

Centelles says he found out what happened on Wednesday morning around 5 a.m. when he woke up and went outside to bring in his 12-year-old Maltese-mix Simba, who likes to wander out a bit during the morning.

"So, I call him, and he doesn't answer. Then I yell at him, and he doesn't answer either," he said. "So I just go to him, and I'm approaching him, and I see that he passed away."

He says the family has lost a few dogs recently to old age, and he assumed the same of Simba.

But he decided to check his cameras just in case.

And that's when he saw the surveillance video of the situation across the street.

It starts with someone taking out the trash and then returning to the garage.

"He turns off the light to pretty much get concealed so that way he doesn't be, he's not seen while he's doing that," said Centelles.

And then you hear the gunshot, Simba barking and running back towards Centelles' home.

Then the person is seen going back into the garage and immediately closing the door.

And in another video, we are not showing because it is too graphic, Simba limping into the yard next to Centelles' other dog, Frostbite, before collapsing and passing away.

It led Centelles to find him just a few hours later.

"That's what we've been trying to figure out these past days with my family. Why would somebody do something like that? And it's hard," said Centelles.

Centelles said he doesn't know the neighbor.

"I've seen him. But I never said a word to him," he said.

Now, Centelles hopes that Ramirez stays behind bars for his actions.

"I want to have the highest hope for me, for my wife, for my kids - For me, for my wife, for my kids, and for Simba to make sure justice is served," he said.

Centelles, who is working with Nevada Voters for Animals during this challenging time, said he hopes the charges are upheld by the Clark County District Attorney's office and that Ramirez stays behind bars.

Court documents show Ramirez was booked on charges of willful or malicious torture of an animal.

But other charges stand out to Centelles and Nevada Voters for Animals.

Those include possessing a gun by a prohibited person and a charge under review for violating probation.