ATLANTA — The fatal police shootings of two black men in Louisiana and Minnesota show the U.S. has a "serious problem," President Barack Obama said Thursday.
He said he shares feelings of "anger, frustration and grief" that police killings have triggered across the country.
[ [READ: Hundreds attend police protest in Atlanta] ]
In his first public reaction to the shootings, Obama said it is clear they were not isolated incidents, adding that the U.S. had "seen such tragedies far too many times."
He said all Americans should be "deeply troubled" by the deaths in Baton Rouge and suburban St. Paul.
Obama's diagnosis of the problem reflected a growing sense of frustration and willingness to speak out publicly about police killings despite the risk of making law enforcement officers feel under attack.
The White House has sought to avoid weighing in on specific cases, particularly while they're being investigated, and Obama said he was limited in what he could say about the facts.
[ [READ: Atlanta educators post powerful statements in response to police shootings] ]
Obama said he is "encouraged" that the Justice Department is conducting a civil rights investigation into the incident in Louisiana, where 37-year-old Alton Sterling was fatally shot Tuesday as he tussled with two white officers outside a convenience store in a predominantly black neighborhood. The shooting was caught on tape and went viral online.
On Wednesday in Minnesota, a man identified as 32-year-old Philando Castile was shot to death during a traffic stop. His girlfriend posted video of the aftermath of his killing live on Facebook, saying he had been shot "for no apparent reason" while reaching for his wallet as an officer had asked.
ALTON STERLING
The lawyers for the 15-year-old son of a Louisiana man shot and killed by police in Baton Rouge are blaming police for overly aggressive behavior.
[READ: Second video shows fatal shooting by Baton Rouge police]
At a news conference held just feet away from where Sterling was killed outside a convenience store, Chris Stewart called the actions of a police officer who shot Sterling "heinous."
Stewart said the killing should never have happened and the two officers should have "de-escalated" the situation instead of ratcheting it up.
Stewart is an Atlanta-based lawyer who has handled high-profile criminal cases before. He is representing Cameron Sterling and his mother, Quinyetta McMillon.
“He’s doing what we always do, which is organize, investigate and prepare,” his partner, Quinton Seay, told Channel 2’s Mark Winne Thursday. “We have our team on the ground. The team back here at home base is providing support.”
Stewart said it was likely the family would file a lawsuit, and added that he and his team would conduct a thorough analysis of police conduct in Baton Rouge.
“Our work is not premised on the assumption that law enforcement officers are bad,” Seay said.
Seay and Stewart’s firm also helped represent the family of Walter Scott, who was shot in the back by a North Charleston, South Carolina, police officer.
Seay says the video in the Sterling case is not as clear cut as the video was in Scott’s case.
A spokesman for the Louisiana governor says the U.S. Justice Department will look into not only whether civil rights were violated in Sterling’s death, but also whether there were any other violations of state and federal law.
Richard Carbo said Thursday that the U.S. attorney's office in Baton Rouge is conducting "all aspects of the investigation."
Carbo said if the U.S. attorney's office finds any violation of state laws and believes the officers should be charged with battery, assault or murder, it will refer that back to the local district attorney for prosecution.
He said: "They won't prosecute it, but they'll do the investigating side of it."
PHILANDO CASTILE
Castile was shot after a traffic stop Wednesday night in Falcon Heights, a suburb of St. Paul. His girlfriend, Diamond Reynolds, broadcast the aftermath of the shooting from inside the car on Facebook. Castile later died.
[READ: Family says man dead after Facebook video captures aftermath of officer-involved shooting]
Minnesota Gov. Mark Dayton says he doesn't think a police officer would have shot and killed a driver who apparently was pulled over for a broken taillight if the driver had been white instead of black.
Dayton said Thursday at a news conference in St. Paul that he thinks the police response was "way over" what was called for when the officer shot Castile several times as he sat in his car Wednesday in the St. Paul suburb of Falcon Heights.
Dayton, a Democrat, says nobody should be killed for a broken taillight or while sitting in their car and that he was "deeply, deeply offended" by Castile's death.
A law enforcement expert says the Twin Cities police officer who fatally shot Castile should have delivered first aid when it was clear he was no longer a threat.
William Moulder is a police consultant and longtime former police chief in Des Moines. Moulder says the officer should have rendered aid to Castile within a minute or two because it was clear there was no threat.
Reynolds and relatives say he wasn't tended to until paramedics arrived more than 10 minutes later.
The Facebook footage shows Castile motionless inside the car for several minutes.
Castile was a 2001 graduate of Central High School in St. Paul who had worked for the school district since he was 19 years old.
A statement on the St. Paul Public Schools website says Castile started working for the district in the Nutrition Services Department in 2002. The statement says when he interviewed for his supervisory position he wore a suit and tie and said his goal was to one day "sit on the other side of this table." He eventually won a promotion and became a respected supervisor.
The statement says colleagues described Castile as "a team player who maintained great relationships with staff and students alike."
Superintendent Valeria Silva says she is "deeply sorry" for Castile's family and calls him "one of our own."
Rep. John Lewis speaks out about shootings
Rep. John Lewis, D-Georgia, released a powerful statement about the shootings on Thursday.
"Like so many Americans, I had a chance to view the murder of Alton Sterling on video. I am not an expert, but to me, it looked like an execution. I cannot understand why any citizen who is complying with police commands should need to fear for his life and then be murdered. The lives of his wife and children are shattered. How can they ever be repaired?
" I cannot imagine the courage that it took for Philando Castillo's friend to remain calm and thoughtful while he lay there beside her bleeding to death. These are not the kinds of experiences that law-abiding citizens should have in the hands of police in America, whether they have a police record or not.
"We must recognize that the African American community is growing weary of the rationale and reasons given to explain these deaths. The taking of black lives seems to be a regular, accepted practice used at will by some police officers without regard for the consequences. The repeated, widespread inability or unwillingness of local courts and prosecutors to punish what appears to be flagrant disregard for human life is hard for any community to bear. We can expect continued protests, and if we are not sensitive to these long-standing, valid concerns, we will have a long, hot summer.
"Police officers need to be trained and re-trained to deal with Americans from different cultures whose lives they are supposed to respect and defend. Leaders in communities and on the national level must address the persistent, inherent bias within police ranks against black and brown citizens. The time is now to say enough is enough".
The Associated Press contributed to this report.