A father and his two young sons were pushing a truck that had run out of gas down a road in December 2012, when a drunk driver plowed into it, killing the boys.
The drunk driver was then shot dead at the scene of the crash near Houston.
On Wednesday, a Texas jury handed down a verdict of not guilty to father David Barajas in the shooting, CNN affiliate KHOU reported.
After the hearing, prosecutor Jeri Yenne stepped in front of cameras to say that she still believed that Barajas killed Jose Banda. Otherwise, the state wouldn't have prosecuted, she said.
"We also know that the jury did not believe that beyond a reasonable doubt," she said. "We respect that."
During the trial Sam Cammack, Barajas' defense attorney, was able to cast some doubt on the charges. He told jurors that the blood of a third, unknown person was found in Banda's car.
He accused authorities of jumping to conclusions.
"Obviously, at least how the evidence developed, they made up their minds at the scene that night and they never considered any other potential leads, even after the DNA came in," KHOU reported Cammack as saying.
The victim was a gang member, the defense argued, and someone else shot him that night in his wrecked car.
The prosecution called an eyewitness who testified that Barajas had left the scene, returned minutes later then leaned into Banda's car. He said he heard a gunshot but didn't see a gun.
Barajas was relieved by the verdict.
"A lot of weight is lifted off my back. I'm still destroyed. I'm missing my sons," he said.
Son David was 12, and Caleb was 11 when they died in the crash. Barajas and his wife have two remaining children.
Barajas said he was praying not only for his family but for Bandas' as well.
"They lost a son, too," he said. "This was a loss for everybody."