The mother of the man who shot and killed three law-enforcement officers in Baton Rouge says her son would "pretty much lose it" when he heard about a black man being shot by police in what he considered an unlawful manner.

Corine Woodley said in an interview with PBS talk show host Tavis Smiley on Thursday that son Gavin Long rented a car several times and drove to locations where black men had been shot by police and would tell her: "Somebody has to do something."

Police gunned down Long, a 29-year-old black man from Kansas City, Missouri, after he shot and killed three officers and wounded three others during a shootout Sunday.

Woodley said during the interview taped in Los Angeles that she believes Long, an Iraq war veteran, suffered from post-traumatic stress disorder.