DALLAS -- One picture tells the story here: a patrol car, turned into a memorial to the police officers murdered Thursday night -- a city's outpouring of love for the latest victims of hate.
Police said a lone gunman -- angry about the recent fatal police shootings of black men -- opened fire on officers as they guarded a peaceful demonstration against the killings in Louisiana and Minnesota this week.
During an hours-long standoff, the gunman told them he was targeting white officers.
Twelve officers were shot -- five killed and seven wounded. It was the deadliest day for U.S. law enforcement since 9/11.
Cellphone video captured the moment that an officer ran toward the gunman and engaged him in a firefight. Seconds later, the officer was hit and the gunman fled.
The shooting started at about 8:45 p.m. Central Time, just as the peaceful protest was ending.
Chants turned to screams as the crowd ran for cover. Eyewitnesses reported shots were coming from above.
"We knew at that point that we needed to turn around and go back the opposite direction," one witness told CBS News. "So kind of natural instinct kicked in and we started telling people, 'Go back that way."
"We got a guy with a long rifle but we don't know where the hell he's at," police scanner traffic reported. "We got one more shooter out here. We got an open window on the side of Lamar. We got rifles hanging out."
Throughout the shooting, the gunman continued to target police. In the chaos, officers ran to the aid of fallen colleagues.
The suspect then fled to a nearby college where police say he shot through windows and doors, and eventually holed up on the second floor of this campus building.
It was there that police attempted to negotiate with 25-year-old Micah Xavier Johnson, a U.S. Army veteran of the Afghan war. In that conversation, they learned of his motives.
"The suspect said he was upset about Black Lives Matter. He said he was upset about the recent police shootings," Dallas Police Chief David Brown said. "He wanted to kill white people, especially white officers.
He also told officers that "the end was near" -- that bombs had been placed throughout the city.
After several hours, negotiations broke down and another gunfight began.
"We saw no other option but to use our bomb robot and place a device on its extension for it to detonate where the suspect was," Brown said. The suspect was killed.
A city and its police department are now in mourning.
"We're hurting," Brown said. "Dallas officers are hurting. We are heartbroken."