A week before Johnson, 25, targeted police in Dallas the normally "chill" military veteran became upset, the friend said.
After travelling to Dallas, Mr Earnest said Mr Obama will "continue the work to bring people together to support our police officers and communities and find common ground by discussing policy ideas for addressing the persistent racial disparities in our criminal justice system". ABC Dallas affiliate WFAA.TV reported witnessing SWAT team members swarming a parking garage near Dallas police headquarters with their weapons drawn, but said it was not clear what the team was responding to. Five police personnel were killed and seven others injured as two snipers opened fire at them during a protest against police shootings of two African-American men in Louisiana and Minnesota, in downtown Dallas Thursday night.
Micah Xavier Johnson, who was himself killed by police, was a USA army veteran who had served in Afghanistan.
Police Chief David Brown revealed at a press conference Friday that police killed Micah Xavier Johnson using a bomb defusing robot equipped with explosives; essentially, an improvised explosive device. He said police lied during a 30-minute interrogation, telling him they had video of him shooting. He served in Afghanistan from November 2013 through July 2014.
"We can learn from what Dallas is doing", he said.
President Barack Obama, who was traveling in Poland, expressed his "deepest condolences" to Rawlings on behalf of the American people.
The deceased suspect has no criminal history and previously served with the USA army reserves in Afghanistan.
One group marched across the Williamsburg Bridge into Brooklyn while another went uptown and marched through Grand Central Terminal, chanting "black lives matter". "We are horrified over these events", he said, "and we stand united with the people and the Police Department in Dallas". Johnson was killed in a confrontation with police. A Minnesota officer shot Philando Castile dead while he was in a auto with a woman and a child, just a day later.
"We believe now that the city is safe and that the suspect is dead and we can move onto healing".
"He said how tragic it is and said that Police are trying to wipe out the black race", said Israel Cooper, who said he'd play pickup basketball with Johnson.
Video from Thursday in Dallas showed protesters marching along a downtown street about half a mile from City Hall when shots erupted and the crowd scattered, seeking cover.
"The news will say what they think but those that knew him know this wasn't like him", Nicole Johnson added in a separate post. In an Instagram video, their names (Lorne Ahrens, Michael Krol, Michael J. Smith, Brent Thompson and Patrick Zamarripa) flash on the screen, one by one.
The day earlier, police in Baton Rouge, Louisiana, shot dead Sterling, 37, while responding to a call alleging he had threatened someone with a gun.