STEVE INSKEEP, HOST:
And I'm Steve Inskeep in Cleveland, Ohio. We are here to witness history. The Republican convention begins here today. It's expected to nominate Donald Trump for president and Mike Pence for vice president. We've seen delegates on the streets, identifiable by the passes they wear to get through security around the arena.
RENEE MONTAGNE, HOST:
Security is said to be a theme of the convention's first La. Here, a recording of a police call in its earliest moments - a theme very much taken from the headlines. On this morning, we will also have the aftermath of a shooting in Baton Rouge, La. Here, a recording of a police call in its earliest moments.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED POLICE OFFICER: Shots fired, officer down. Shots fired, officer down.
MONTAGNE: Three officers lay dead after the gunman opened fire in the same city that two weeks ago a video captured the police-shooting death of Alton Sterling, a black man. NPR's David Schaper is in Baton Rouge and joins us for more. Good morning.
DAVID SCHAPER, BYLINE: Good morning.
MONTAGNE: How exactly did this start?
SCHAPER: Well, police received a call of a man dressed in black, armed with a rifle, not far from the police station. And according to police, this was about 8:40 in the morning. Two officers were at a nearby convenience store and saw the suspect. They started to approach him and then were just met with a hail of gunfire in what the mayor describes here as an ambush attack. Other officers responding to the scene returned fire. It became a shootout. Just a few minutes after all this started, Johnny O'Bryant came driving by.
JOHNNY O'BRYANT: And as soon as I turned onto Drusillah, I heard something like, pop, pop, pop - sounded like gunfire. And as I got closer, I started seeing police lights.
SCHAPER: He says 20 to 30 police vehicles quickly swarmed all around.
O'BRYANT: And a officer ran up and told me that three of his comrades were down and that he needed me to stop because they was trying to get me and the people in other vehicles out of the line of fire.
SCHAPER: In all, about six officers were hit with bullets - three of them killed, three of them wounded, one of whom is fighting for his life, according to his chief.
INSKEEP: David, as this story spread yesterday, people across this country must have been asking, who is responsible for this? What does it mean, really, is the question there. So what is known about the shooter?
SCHAPER: The shooter is identified by law enforcement authorities as 29-year-old Gavin Long. He's from Kansas City, Mo. He's African-American. He was a decorated former Marine who served a tour in Iraq and was honorably discharged six years ago. He may have belonged to some anti-government groups. Certain social media posts suggest he may have been enraged by recent police shootings of black men, including the killing of Alton Sterling here in Baton Rouge earlier this month. But in talking with local and state police officials last night, they would not comment on any possible motive. One interesting note is that there were no big protests or rallies last night, not even a big, organized vigil. One woman said people might be just too afraid to come out.
MONTAGNE: That's NPR's David Schaper speaking to us from Baton Rouge, La. Thanks very much.
SCHAPER: Thank you, Renee. Transcript provided by NPR, Copyright NPR.