A Houston man on trial for fatally shooting his neighbor says he was acting in self defense and his home video can prove it.

Rodriguez, a former firefighter, was recording his argument with neighbors, when he shot and killed Kelly Danaher, an elementary school teacher, and wounded two other people in May 2010. The 22-minute homemade video is the key to the trial, but what's on the video might be in the eye of the beholder.

"This is a difficult defense to mount," says Dana Cole, legal analyst and defense attorney. "He had no injury, he brought a gun to a noise complaint, and it appeared he was escalating it, by baiting the party-goers."

It was after midnight when Rodriguez, complaining to police over the phone that the music was too loud, walked up to Danaher's driveway with a flashlight and gun.

On the video, Rodriguez can be heard talking to a 911 operator, saying, "I'm running the video camera right now and I'm talking to you and I mean, I'm scared to death here."

In the unfolding confrontation between Rodriguez and several unidentified men, one yells, "Tell you what, pal, you just pulled a gun on the wrong [expletive], OK?"

When one of the party-goers saw Rodriguez's gun, he suggested he is getting his own. "When I go in that house and come back," he warned, "don't think I won't be equal to you, baby."

"It's about to get out of hand sir, please help me. Please help me, my life is in danger now…," Rodriguez told police over the phone. "Now, I'm standing my ground here. Now, these people are going to try and kill me."

Seconds later, a fight about loud music ends with the crack of gunfire.

"Look, I'm not losing to these people anymore," Rodriguez said. "I'm just totally going to stay back, because they're drunk, they're…"

Rodriguez is interrupted by wild laughter, and then the sound of gunfire, before the tape stops as Rodriguez is tackled to the ground. In addition to the shot that killed Danaher, Houston Fire Capt. Ricky Johnson and Marshall Stetson received multiple gunshot wounds after the camera stopped recording. Rodriguez, a father of six, walked away from the incident unharmed.

The trial is expected to last about a week.

ABC News' Toni Wilson contributed to this report.