Dallas police say four officers were shot and killed, and seven others wounded by snipers during a protest Thursday night against recent deadly police shootings. The slain officers included three Dallas PD officers and one officer with DART, the local transportation system. Several other officers were in critical condition.
Two snipers shot down at the officers from an "elevated position," Dallas police chief David Brown said in a statement. He raised the question of how the snipers knew the route of the protest in order to position themselves.
"They planned to injure and kill as many law enforcement officers as they could," Chief Brown said.
Dallas police conducted a massive mobilization in the downtown after the shootings, creating a massive crime scene. Buses and public transportation was shut down, stranding hundreds of people in downtown Dallas.
Early Friday, Chief Brown said that police were still in negotiations with a man with whom they exchanged gunfire. That man said "the end is coming" and that he wanted to hurt police. The man also said there were bombs scattered in the downtown.
Earlier, police released on Twitter a man who they said was a person of interest. That man has turned himself in. Police have also arrested two men in camouflage gear who were seen in the area in a Mercedes.
Chief Brown said they were concerned that there may be other suspects still at large.
The city of Dallas tweeted the following photo of a person of interest who, according to Dallas police, has been identified by witnesses. A man who said he was the suspect's brother said his brother, whom he identified as Mark Hughes, was not a shooter and had been at the protest with his gun which he said was lawfully registered. The brother, Corey Hughes, said he was one of the organizers of the protest.
Both brothers are speaking with police as of early Friday.
This may be one of our suspects. Help us find him. pic.twitter.com/jl16j80rL2— Emily Black PIO (@EmilyPIODallas) July 8, 2016
The shots were fired at approximately 8:45 p.m. CST on Thursday night, as hundreds of protesters marched in downtown Dallas to protest recent police shootings in Minnesota and Louisiana. The Dallas protests were one of various protests held across the nation Thursday night in New York, Washington, D.C., Miami, Baton Rouge and other cities.
According to KTVT, the officers were shot around the intersection of Market and Commerce in downtown Dallas.
"At first I thought it was a firecracker," one witness, Clarissa Myles, told CBS Affiliate KTVT. "I saw at least 30 shots go off."
"I knew it was a high caliber rifle, just from the pause and sound itself," one witness, Jamal Johnson, told KTVT. He described terrified protesters rushing to use a bus station for cover as shots rang out.
Another witness said it appeared the shots came from the roof of a parking garage.
Earlier tonight, in cities across the country, protesters pounded the pavement to express their heartbreak, fury and frustration over the shooting deaths of two black men, Alton Sterling and Philando Castile, this week. Video footage of both murders, shared widely on the internet, has helped narrow the emotional distance the American public usually feels in police shootings of black Americans.
In St. Paul, Minnesota -- where Philando Castile was killed during a routine traffic stop with his girlfriend watching -- hundreds marched to the Governor's Mansion alongside the victim's mother, Valerie Castile, who is just one day into mourning her son's death, CBS Minneapolis affiliate WCCO reported.
Minnesota Governor Mark Dayton has said that, in his opinion, police officers acted "way in excess" in shooting and killing Castile and would not have done so if he was white. The moment after Castile's shooting was captured by Castile's girlfriend, Lavisha Reynolds, who turned on Facebook's live streaming feature seconds after her boyfriend was shot and narrated the entire encounter to her personal network.
In Baton Rouge, Louisiana, where Alton Sterling was shot, protesters gathered outside the Living Faith Christian Center with fists raised and chants on "No justice, no peace," according to CBS Baton Rouge affiliate WAFB. Louisiana Governor John Bel Edwards addressed protesters at a prayer vigil directly before the protest.
In New York, approximately 1,000 demonstrators marched from Union Square to Times Square.
In Washington, D.C., throngs of protesters gathered outside Capitol Hill and joined in song, swaying side to side to "We Shall Overcome." They chanted the now-familiar refrains: "Black lives matter" and "Hands up, don't shoot."
In Chicago, one group of protesters gathered outside a South Side police headquarters before taking their rally to the Dan Ryan Expressway, where they blocked traffic for several minutes, CBS Chicago affiliate WBBM reported. Another group of demonstrators marched downtown and reportedly tried to take their protest into the city's popular "Taste of Chicago" event in Grant Park, WBBM reported.
This is a developing story. For updates you can find this story on CBS News.