Police cornered that suspect in a parking structure in the heart of the city after the sniper slayings of five officers.
The deceased suspect was identified as 25-year-old Micah Xavier Johnson, an Army veteran from the Dallas suburb of Mesquite.
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While in the hours after the Thursday night shooting, several people were detained and identified as possible suspects, on Friday officials said they determined that Johnson had acted alone.
"We believe, given the facts that we have today that Mr. Johnson, now deceased, was the lone shooter in this incident," Dallas Mayor Mike Rawlings said.
He said initial reports of at least two shooters were a result of the confusion in the initial moments after the shooting, as well as Johnson's training in how to move around while shooting.
"This was a mobile shooter that had written manifestos on how to shoot and move, shoot and move," Rawlings said. "And he did that. He did his damage. But we did our damage to him as well."
"And we believe now that the city is safe."
Homeland Security Secretary Jeh Johnson said at a news conference Friday in New York City that the gunman doesn't appear to have had any known "links to or inspiration from any international terrorist organization."
Defense officials confirmed that the gunman served in the Army Reserves from March 2009 to April 2015. He was trained and served as a carpentry and masonry specialist.
According to service records released by the Army, Micah Johnson deployed to Afghanistan from November 2013 to July 2014. He had the rank of private first class.
Dallas Police Chief David Brown said that overnight standoff ended when police detonated an explosive about four hours after the attack began. Authorities said the explosive was attached to the extended arm of a robot to protect officers.
Before he was killed, the suspect told crisis negotiators that he was upset about the Black Lives Matter movement and the recent fatal police shootings of black men, Brown said. The suspect also said he wanted to kill white people, especially white police officers.
The ambush attack happened during protests over this week's fatal police shootings in Louisiana and Minnesota of two black men. A Black Lives Matter march was underway through the streets of downtown Dallas when the shots rang out around 8:45 p.m.
Hundreds of protesters scrambled and ran for safety. Witnesses said the shooting went on for close to 45 minutes.
Authorities say the attack was very well planned, but it remained unclear how many shooters were involved. Authorities initially said three suspects were in custody and the fourth dead. Hours later, officials were vague and would not discuss details.
When the shooting finally came to an end, five officers were dead and seven officers were wounded. Two civilians were also wounded in the shooting.
In addition to comments he made about wanting to kill white police officers, the suspect also hinted as possible explosive devices planted throughout the city. Based on those statements, police searched the city for explosives but did not find any.
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Speaking at an interfaith prayer vigil Friday in downtown Dallas, Brown called the shootings a "well-thought-out evil tragedy," saying his force "won't rest until we bring everyone involved to justice."
Christian, Jewish and Muslim faiths were represented at the vigil that was attended by hundreds.
Incredible turnout came in support of our officers. pic.twitter.com/ofEy7QX5k5— Dallas Police Depart (@DallasPD) July 8, 2016
President Barack Obama made an official statement about the tragedy in Texas Friday morning, where he was attending a NATO summit in Poland. He asked Americans to remember the victims and survivors of the shootings, as well as their families.
The Associated Press contributed to this report.