BATON ROUGE, La. (AP) - Last summer, a military veteran who was angry over the police treatment of black men ambushed law enforcement officers in Baton Rouge, killing three and wounding three before a sniper fatally shot him.

On Friday, District Attorney Hillar Moore III planned to hold a news conference to release videos and a report on the July 17 rampage. Moore's office reviews all fatal police shootings in the parish to determine whether a killing was legally justified, though in this case there has been no suggestion that officers acted inappropriately.

Police said Gavin Long, a 29-year-old black man from Kansas City, Missouri, sought out law enforcement when he attacked the officers that Sunday morning. Long killed Baton Rouge officers Montrell Jackson, 32, and Matthew Gerald, 41, and East Baton Rouge Parish Sheriff's Deputy Brad Garafola, 45.

The attack occurred amid simmering tensions nationwide over the treatment of blacks by police. Just 10 days earlier, a sniper fired on a group of police officers in Dallas, killing five officers and wounding nine others. Two civilians were also wounded. Two days before that, an officer in Baton Rouge killed 37-year-old Alton Sterling, a black man, during a struggle that was captured on two cellphone videos and sparked nightly protests in the city.