POINCIANA, Fla. — Brandon Gonzales did not shoot anyone.
But for more than a week this fall, the authorities in Texas were convinced that he was the gunman who killed two people and wounded several others at a homecoming party. With no chance of posting his $1 million bail, Mr. Gonzales passed his days in an orange jumpsuit poring over the Bible, writing out prayers, trying not to think about how he could face execution if convicted.
“Dear Lord, I am a innocent man and a scared man,” Mr. Gonzales, 23, wrote in jail. “I have done no wrong and they have no evidence.”
Mr. Gonzales’s arrest, and his eventual release with charges dropped, was the result, the authorities now say, of a misidentification by a witness in the tense hours after the shooting. In the chaotic aftermath of violence — when news cameras are swarming, residents are demanding answers and conspiracy theories are swirling online — mistakes often emerge.
Sometimes, the number of assailants is reported to be higher than it really is. Other times, victim counts are mistaken. But sometimes, the errors are more damaging, and as Mr. Gonzales’s case shows, inaccurate information spreads so quickly that the fallout can never be fully contained.
“It shocks me how I can look up my name on Google or on YouTube, and it’s going to pop up everything,” Mr. Gonzales said recently in Florida, where he moved to escape the notoriety that came with his arrest, but has still been unable to find steady work. “My kids, their kids, can always look up and they can see, oh, he was arrested for capital murder.”
The potential for inaccurate information about a tragedy to spread quickly and ruin lives has drawn increased attention amid a high number of violent gun attacks this year and since the release of the movie “Richard Jewell,” which tells the story of a man who was wrongly implicated by the news media in a bombing during the 1996 Atlanta Olympics.
In the highly competitive news environment that follows a mass shooting, reporters sometimes fall for malicious disinformation online, such as after the school shooting in Parkland, Fla., or cite unnamed sources who may or may not be right. In other instances, when the police provide on-the-record information that later turns out to be wrong, news articles initially report information incorrectly and sometimes those details continue to live online. Like many local and national news outlets, The New York Times wrote about Mr. Gonzales’s arrest and published his mug shot. The Times also wrote an article when he was released.
“There’s balancing priorities between wanting to get the facts right, and knowing that the first information you get is usually inaccurate or wrong, and the public’s right to know,” said Chuck Wexler, who leads the Police Executive Research Forum, which advises departments on best practices. He described briefing reporters after a mass shooting as “piecing together a jigsaw puzzle instantly.”
In Santa Clarita, Calif., where a gunman shot five people last month at a high school, the sheriff’s office was initially duped by an Instagram account that they wrongly linked to the gunman. Reporters, who had been reassured by law enforcement officials vouching for the postings, had to backtrack after publishing excerpts.
In Jersey City, N.J., the authorities initially said a shooting at a kosher market this month appeared to be random. Soon after, the gunmen were linked to a fringe group that espouses anti-Semitic views, and the mayor called the killings a hate crime.
And in Las Vegas, where 58 people died in 2017 when a gunman fired more than 1,000 rounds into a crowd at a music festival, conspiracy theorists spewed wild, unsubstantiated claims that gained traction online. The problem was not helped by the police releasing a timeline of events that contained several errors and that twice had to be corrected.
“Although it hurts, and it can ruin, an agency’s or individual’s credibility, I think it’s more important to acknowledge as soon as we realize something is inaccurate,” said Assistant Sheriff Charles L. Hank III of the Las Vegas police.
Many police departments now train for the eventuality of a mass shooting, using the hard-earned lessons of places that have already endured one. Daniel Oates, who was the police chief in Aurora, Colo., during the 2012 movie theater shooting, compiled a list of 24 points of detailed advice that he shared with colleagues in other cities. Among them: Focus on the victims, prepare to combat online conspiracy theorists and “end the media circus as soon as you reasonably can.”
Mr. Oates, now retired, recalled showing up at the scene of the Aurora shooting to hear that officers were searching for a second gunman who turned out not to exist.
“It always comes back that people see more shooters than there are,” Mr. Oates said. In his first statement to the press, perhaps 90 minutes after the shooting, Mr. Oates correctly told reporters that the only shooter was in custody, but slightly overstated the number of victims.
Because mass shootings are so chaotic and unintentional mistakes have happened so frequently, police chiefs now make a point of qualifying their early statements. They say their information is preliminary and subject to change, or they give an estimate of the number of casualties rather than a firm number.
But failing to say anything increases the possibility of rumors and conspiracy theories spreading online, chiefs said.
“We just tried to overwhelm the public with our Twitter feed,” said John Mina, who was the police chief in Orlando, Fla., when 49 people were killed at a gay nightclub in 2016. He said a rumor that there had in fact been two gunmen at the nightclub — there was only one — proved especially “hard to squash.”
This October, sheriff’s deputies in another city responded to another mass shooting at another late-night party venue. A gunman had stormed into an event hall near Greenville, Texas, where hundreds of college students and other young adults were wearing Halloween costumes and celebrating homecoming.
Randy Meeks, the county sheriff in Greenville, said in a statement that mass shootings in rural areas like his were especially difficult because of the limited number of officers available to provide backup and secure the crime scene.
“The deputy that was on scene investigating a different call was immediately faced with, in his words, a mass of people running out of a building all coming to him for help when the shots were still being fired,” Sheriff Meeks said.
Mr. Gonzales had been in the club earlier that night. But he had stepped outside and was in parked car nearby when he saw the mass of panicked partygoers run past. Someone was shooting, they told him.
Mr. Gonzales made it home later that night, relieved that he and his friends were not hurt. But a couple days later, when Mr. Gonzales showed up to his job at a car dealership, he was swarmed by police officers. They took him downtown and told him a witness had named him as the gunman.
For days, Mr. Gonzales sat in the Hunt County Jail. Prosecutors had filed capital murder charges. He figured it could be year or more before he would have a chance to clear his name at trial.
Then, abruptly and without much explanation, things changed. Just over a week after he was booked, Mr. Gonzales was sent home and the charges were dropped. Sheriff Meeks said investigators found evidence showing that Mr. Gonzales did not commit the crime.
Mr. Gonzales, now a free man, is no longer the same man.
He left Greenville, his hometown, a few days after his release. The last straw, he said, was when someone filmed him shopping at the local Walmart.
But his new life in Florida, where he lives with relatives in a quiet, palm-lined neighborhood in the Orlando exurbs, has not quite gone as planned.
Mr. Gonzales, who has experience operating a forklift, met with one prospective employer, but he said they suggested that he wait until news of the arrest faded. Other applications have failed to result in jobs. He assumes the mug shot that comes up when his name is Googled plays a role.
“I fear people are not going to give me a chance, but I’m hoping they do,” Mr. Gonzales said. “I will never get back to my old life. I’ve swallowed that.”
Kitty Bennett contributed research from New York.