Joe Horn, 62, shot the two men in November after he saw them crawling out the windows of a neighbor's house in the Houston suburb of Pasadena, carrying bags of the neighbor's possessions.
Horn, a retired grandfather, called 911 and told the dispatcher he had a shotgun and was going to kill them. The dispatcher pleaded with him not to go outside, but Horn confronted the men with a 12-gauge shotgun and shot both in the back.
"The message we're trying to send today is the criminal justice system works," Harris County District Attorney Kenneth Magidson told reporters at the courthouse.
Horn's attorney, Tom Lambright, said his client was relieved by the grand jury's decision and never wanted to hurt anyone.
"He wasn't trying to take matters into his own hands," Lambright said. "He was scared. He was not playing cowboy."
Horn did not speak with reporters on Monday.
A large red sign with the words "No Trespass" on it blocked the path to his front door and a handwritten sign on the door said "Please no media" "No Trespassing" and "Do not knock or ring bell." A couple of neighbors also had signs on their doors asking media to leave them alone.
A few police cars patrolled the area near Horn's home.
Lambright reiterated to reporters that Horn believed the two men had broken into his neighbor's home and that he shot them out of fear for his life when they came into his yard and threatened him.
"He wasn't acting like a vigilante," Lambright said. "He was well within his rights to do what he was doing."
The two suspected burglars, Hernando Riascos Torres, 38, and Diego Ortiz, 30, were unemployed illegal immigrants from Colombia. Torres was deported to Colombia in 1999 after a 1994 cocaine-related conviction.
The incident touched off protests from civil rights activists who said the shooting was racially motivated and that Horn took the law into his own hands. Horn's supporters defended his actions, saying he was protecting himself and being a good neighbor to a homeowner who was out of town.
"I understand the concerns of some in the community regarding Mr. Horn's conduct," Magidson said. "The use of deadly force is carefully limited in Texas law to certain circumstances ... In this case, however, the grand jury concluded that Mr. Horn use of deadly force did not rise to a criminal offense."
The city of Pasadena, where protesters and defenders of Horn engaged in counter-demonstrations, pledged to keep its police force staffed enough to protect its citizens.
"The obvious lessons that can be drawn from (the Horn case) are that criminal activities are inherently a dangerous lifestyle, and the prevention and pursuit of those involved in criminal actions are best left to the police," said the statement issued by city spokeswoman Jennifer Banks.
Magidson said nine of the 12 grand jurors would have had to vote in favor of an indictment in order for Horn to be charged.
Grand jurors had to consider two issues: the intentional killing of another person and whether the killing was justified either by self defense or the defense of property, Magidson said.
Horn testified before the grand jury for about 1½ hours last week, Lambright said.
Keith Hampton, a Houston attorney not connected with the case, said he didn't expect Horn to be indicted.
"This is a real conservative county," he said. "A lot of folks in Houston and Harris County are saying this man was doing a good thing."
In the 911 call, a dispatcher urges Horn to stay inside his house and not risk lives
"Don't go outside the house," the 911 operator pleaded. "You're gonna get yourself shot if you go outside that house with a gun. I don't care what you think."
"You wanna make a bet?" Horn answered. "I'm gonna kill 'em."
After the shooting, he redialed 911.
"I had no choice," he said, his voice shaking. "They came in the front yard with me, man. I had no choice. Get somebody over here quick."
Lambright said the 911 call gave the public the wrong impression about Horn and what happened that day.
"It's a very sad thing that occurred," Lambright said of the shootings.
Texas law allows people to use deadly force to protect themselves if it is reasonable to believe they are in mortal danger. In limited circumstances, people also can use deadly force to protect their neighbor's property; for example, if a homeowner asks a neighbor to watch over his property while he's out of town.
It's not clear whether the neighbor whose home was burglarized asked Horn to watch over his house.