Shots rang out in quick succession as a peaceful protest in Dallas against police violence took a violent turn Thursday night, leaving 11 officers injured, four fatally.
Here's what we know:
Dallas police officers, Dallas Area Rapid Transit officers shot
Police confirmed those injured included officers with the Dallas Police Department and Dallas Area Rapid Transit. In a news release sent around 11 p.m. local time, authorities said two officers were in surgery and three were in critical condition.
In a subsequent update, authorities said 11 officers had been injured, and four of them had died of their wounds.
The officers have not been identified, except to say three of the officers were with the Dallas Police Department and one was a Rapid Transit officer.
Police Chief David O. Brown said at a news conference Thursday night that authorities were in the process of notifying the victims' families.
Person of interest turns himself in, suspects in custody
Officers are negotiating with a suspect who has been in a shootout with SWAT officers at a downtown Dallas parking garage, Brown said. The man has not been cooperative with negotiators.
"(He) has told our negotiators that the end is coming and that there are bombs all over the place, in (the) garage and in downtown, so we are being very careful," Brown said.
A woman was in custody, although police did not elaborate on her connection to the shooting.
Authorities questioned two people after a police officer spotted one of them carrying a camouflage bag and walking quickly in the area. The person threw the bag into the back of a Mercedes and sped away, police said.
Brown said at a late-night news conference both people in the vehicle were in custody.
A man identified as a person of interest turned himself in to authorities after the shooting. His picture was widely shared after Dallas police identified him, although the man's brother, Corey Hughes, insisted that his brother gave his gun to police.
"I knew, I knew because he had his firearm that a cop could misidentify him ... so I made sure he gave his gun to a cop," Hughes, one of the protest's organizers, told KTVT.
He said his brother's gun was not loaded and that his brother, identified as Mark Hughes, brought the gun to the peaceful protest because "he was exercising his rights."
"We still don't have a complete comfort level that we have all the suspects (in custody)," Brown said.
Bomb squad responding to suspicious package
Brown said the police department received a bomb threat in relation to Thursday's shooting. A suspicious package was found near the area where SWAT officers apprehended the unidentified suspect.
The Dallas Police Department bomb squad is investigating the package.
At least two gunman attacked from elevated positions, police say
Shots rang out one after another around 9 p.m. as the peaceful protest came to an end, Dallas Mayor Mike Rawlings said.
At least two snipers are believed to have opened fire from nearby parking garages. Brown said the shooters appeared to have triangulated their positions. The attack appears to have been planned.
About 800 people participated in the demonstration, which came in the wake of two recent fatal shootings by police.
On Wednesday, a Minnesota officer fatally shot Philando Castile while he was in a car with a woman and a child in a St. Paul suburb. The aftermath of the shooting was purportedly livestreamed in a widely shared Facebook video.
A day earlier, Alton Sterling was shot in Louisiana after being pinned to the pavement by two officers. That, too, was captured on a cellphone video.
Roughly 100 officers were in the area "to protect demonstrators and the surrounding area," Rawlings said.
Mayor: 'Our worst nightmare happened'
Rawlings described the shooting as "our worst nightmare," while speaking to reporters Thursday night.
"It is a heartbreaking moment for the city of Dallas," he said.
Brown asked for the public's prayers on behalf of the victims and their families and asked "that you give our officers strength, to catch these suspects and bring them to justice tonight."
Authorities were in contact with the Bureau of Alcohol, Tobacco, Firearms and Explosives and the FBI.
The Associated Press contributed to this report.
WFTV
