The words brought tears to Gov. John Bel Edwards' eyes.

“Montrell was my everything," slain Baton Rouge Police Officer Montrell Jackson's widow, Trenisha, wrote in a note that was read Monday during an somber briefing on the fatal shooting in Baton Rouge that left Jackson and two other officers dead Sunday.

“I know without a shadow of a doubt, he loved his job and his city," Baton Rouge Police Chief Carl Dabadie read aloud, his voice cracking as he recited the young widow's words. "Knowing this is what gives me a little peace and comfort. I know he made the ultimate sacrifice and paid the ultimate price in doing what he loved, protecting and serving a city that he loved."

After an emotional 24 hours, Edwards, Dabadie and other law enforcement leaders addressed a packed room full of reporters from across the country on Monday, offering the latest briefing on what happened Sunday, when three officers were killed and three others injured by a gunman from Missouri with an apparent vendetta against law enforcement.

Edwards' blood-shot eyes welled with tears at several points as leaders hailed the slain officers as heroes and struggled to explain the motive behind the attack.

"This was a diabolical attack on the very fabric of society," Edwards said, a deep row of television cameras glaring back at him. "That's not hyperbole. That's not an overstatement."

Officials have formally named Gavin Long, of Kansas City, as the shooter. Long was killed by a Baton Rouge police sniper, ending the deadly encounter Sunday morning.

Edwards called the shooting "pure evil."

Later the governor, a Democrat who took office in January and has been repeatedly thrust into the national spotlight for tragedies, attempted to explain his tears.

"I don't know if it's good or bad for our governor to cry, but I do on occasions like this," said Edwards, whose family has a long history in law enforcement. "It hits home for all of us."

On Monday as the picture began to come into focus, President Barack Obama called the families of Jackson, BRPD Officer Matthew Gerald and East Baton Rouge Deputy Sheriff Brad Garafola to offer condolences.

The Republican National Convention began with a moment of silence honoring the slain officers.

"They're our genuine heroes," RNC Chairman Reince Priebus said. "Our nation grieves when we see these awful killings."

Obama and Edwards have ordered flags flown at half-staff across the state and across the nation in memory of Jackson, Gerald, Garafola and the injured officers.

"This individual from out of state came here and yesterday engaged in this horrific act of violence directed at our law enforcement community," Edwards said.

Edwards read an excerpt of a note Jackson recently posted to Facebook that has gone viral since news of the shooting made national headlines and dominated cable talk shows Sunday evening.

"This city must and will get better," Jackson had written in the excerpt read by Edwards. "I’m working in these streets so any protesters, officers, friends, family or whoever, if you see me and need a hug or want to say a prayer I got you.”

Edwards said he hopes in the coming days to have an open dialogue with community and faith leaders about bringing unity to the city following the attack on officers and the death of Alton Sterling, a 37-year-old black man who was killed by Baton Rouge police during an altercation in a convenience store parking lot less than two weeks ago. The U.S. Justice Department and FBI are investigating Sterling's death, which also drew national attention as video of the deadly shooting circulated online. 

Edwards and other leaders repeatedly stressed Long's status as someone not from Louisiana. Officials, citing the early stage of the investigation, still haven't revealed what specifically brought Long to Baton Rouge or how long he was here. 

Long had referenced Sterling's death on social media, and some have speculated that it could have been a driving factor behind his decision to come to Baton Rouge but that hasn't been confirmed.

"He came here from somewhere else to do harm to our community, specifically the law enforcement in our community," Edwards said.

Much of Monday's briefing focused on an overview account of the shooting itself or the backgrounds of the officers involved. Edmonson at several points said it was too early to answer specific questions about Long's timeline or other details still under investigation.

"We will get through this," Sheriff Sid Gautreaux said, echoing Jackson's words, written on Facebook two weeks before he was shot and killed on the job. "Baton Rouge is better than this."

Follow Elizabeth Crisp on Twitter, @elizabethcrisp.