Three police officers were killed and three more were wounded Sunday morning in a shooting in Baton Rouge, La., a city already reeling from the the death of an African-American man killed in a confrontation with police earlier this month.

Brad Garafola, Montrell Jackson and Matthew Gerald were shot and killed when they responded to reports of a man armed with an assault rifle. 

ADVERTISEMENT

Gavin Long, 29, was shot and killed at the scene and was identified as the shooter by media reports. Long is reportedly from Kansas City, Mo., and briefly attended the University of Alabama.

The Daily Beast reported that Long served in the Marines from 2005 to 2010 as a data network specialist. He deployed to Japan and spent seven months in Iraq.

University spokesman Chris Bryant said Long was a student for one semester in the spring of 2012, The Associated Press reported.

Bryant says university police had no interaction with Long during that time.

Details about Long's background were not immediately available, although Sen. Bill Cassidy (R-La.), in an interview with CNN, said he had been told that Long's Facebook page suggested leanings toward hate groups. Asked what hate groups, Cassidy said he did not know.

Long left an online trail that may hint at his motivation, The Guardian reported Sunday night. He appears to have visited web sites focused on complaints about the treatment of black people by police. 

Police also said there was not an "active shooter" situation in Baton Rouge, suggesting they believe Long may have acted alone.

The killings of the police officers comes just more than a week after five police officers were killed in Dallas by a man who police said was targeting white people, and specifically white police officers. 

Fears of racial unrest and the targeting of police have been at a high since those shootings, and the deaths of two black men in police shootings in Baton Rouge and the Twin Cities region of Minnesota. 

President Obama, who spoke at a memorial service for the fallen Dallas officers this week, urged Americans to watch their words and their tone in a rare Sunday appearance at the White House press briefing room to respond to the latest shootings. 

"We may not yet know the motives for this attack, but I want to be clear: There is no justification for violence against law enforcement. None. These attacks are the work of cowards who speak for no one," Obama said.

"They right no wrongs. They advance no causes. The officers in Baton Rouge, the officers in Dallas — they were our fellow Americans, part of our community, part of our country, with people who loved and needed them and who need us now, all of us, to be at our best."

 
"How many law enforcement and people have to die because of a lack of leadership in our country?" Trump, the presumptive GOP presidential nominee, said in a post on Twitter. "We demand law and order." 

Trump has been referring to himself as the law and order candidate for the last week. 

Louisiana Gov. John Bel Edwards (D) called the attack "unjustifiable" and asked for the nation to join him in praying for the victims. 

"The violence, the hatred, just has to stop," Edwards said while addressing the press on Sunday afternoon. 

"That men risking their lives to protect and serve this community were taken out the way that they were — they are real life, everyday heroes," he said. 

Edwards noted that local, state and federal authorities will assist with the investigation and said he spoke with President Obama earlier in the day. 

The shooting began shortly after 9 a.m., when someone called 911 to report a “suspicious person walking down Airline Highway with an assault rifle,” officials said. It’s unclear whether police were lured to the location by the gunman.

Police used a robot to check for explosives around the body of the suspect who was shot and killed, the New York Post reported.

While some reports indicated that the shooter killed by police may have acted alone, the AP reported earlier on Sunday that two persons of interest had been detained. 

Department of Homeland Security chief Jeh Johnson was also briefed on the shooting Sunday, according to ABC News, and has directed the "full weight of the Department's resources" to assist. 

This story was updated at 9:19 p.m.