Photos show Baton Rouge gunman shooting at police with assault rifle

Louisiana authorities said on Monday there's no question that gunman Gavin Long "intentionally targeted and assassinated" police in Baton Rouge, killing three officers and wounding three others.

"It was a calculated act," Louisiana State Police Superintendent Mike Edmonson said. "His movements were intense, combative." Two Baton Rouge police officers and one sheriff's deputy were killed in the attack. Another deputy is fighting for his life, and two more are injured.

Edmonson said investigators believe that Long, a Marine who served in Iraq, had been in Baton Rouge for several days before the attack, which took place on his 29th birthday. The shooting occurred 12 days after white police officers in the city fatally shot black man Alton Sterling, an incident that provoked protests across the city and nation.

"This was a diabolical attack on the fabric of our society," Louisiana Governor John Bel Edwards said. "There is nothing more fundamentally important than maintaining law and order… that is what he attacked. That's not justice for Alton Sterling or anyone else. It's not constructive. It's pure, unadulterated evil."

During the news conference, authorities used a map to explain Long's movements between various parking lots in a Baton Rouge shopping center, showing how he bypassed civilians in search of police officers.

"He was running, he was in shape, clearly concentrated on exactly what he was trying to do," Edmonson said. "He was articulate in all manners of engagement."

Baton Rouge police chief Carl Dabadie said investigators believe that Long intended to go to police headquarters, located less than a mile away, to kill more cops. Police released images from surveillance cameras that showed the attack in progress, as well as the assault rifles and a handgun that Long used.