Five people — including four Marines and the sole gunman — are dead following shootings at two separate military centers in Chattanooga, Tennessee.

A police officer was also wounded and suffered non-life threatening injuries.

The suspected shooter has been ID'd as Muhammad Youssef Abdulazeez.

See further details, photos and more information on Adbulazeez, here.

Chattanooga Mayor Andy Berke confirmed the five deaths at a news conference Thursday. The U.S. attorney in Tennessee said this will be investigated as an act of domestic terrorism.

Fox News chief intelligence correspondent Catherine Herridge said that it is "highly unusual" for the FBI to already be taking the lead in the investigation and have several hundred agents heading to the scene.

Herridge said officials confirmed the attacker was not a military member and did not have known ties to the victims.

The shooting began at around 11 a.m. at U.S. Naval Recruiting on Lee Highway, where the suspect is believed to have fired in rapid succession for a period of minutes, then sped away in a silver Mustang.

A police officer was wounded at that location, but his injuries are not life threatening.

Smith said the suspect then drove about seven miles to the U.S. Naval Reserve Center on Amnicola Highway. That’s where the four Marines were shot before the suspect was killed by authorities.

A Chattanooga Times Free Press reporter heard two shots fired in the nearby woods, where it’s believed that the shooter was taken down.

The officer involved in the shooting is in stable condition.

Chattanooga Mayor Andy Berke called the shooting "a very terrible situation."

A woman who says she witnessed the Chattanooga shooting told the Associated Press that she heard a barrage of gunfire.

"It was rapid fire, like pow pow pow pow, so quickly. The next thing I knew there were police cars coming from every direction," said Marilyn Hutcheson, who works at a Binswanger Glass. [...] Hutcheson says she ran inside, where she remains with other employees and a customer. The gunfire continued with occasional bursts she estimated for 20 minutes. "We're apprehensive," Hutcheson said. "Not knowing what transpired, if it was a grievance or terroristic related, we just don't know."

Hutcheson was on "Happening Now" this afternoon. Watch the interview below.

President Barack Obama spoke from the White House about the tragic shooting.

"My main message right now is obviously, the deepest sympathies to the American people," Obama stated. "To the four Marines that have been killed, it has been a heartbreaking circumstance for these individuals who have served our country with great valor to be killed in this fashion."

He said that all of the details are not yet known, but a full investigation is taking place.

Watch a video of Obama's remarks here.

John Roberts reported during "On The Record" that Abdulazeez graduated from the University of Tennessee at Chattanooga with a Bachelor of Science degree in electrical engineering in 2012.

Abdulazeez graduated from Red Bank High School with a yearbook photo featuring the quote, "My name causes national security alerts. What does yours do?”

Roberts also reported that the shooter was arrested for a DUI in April of this year.

Watch Roberts' report from "On The Record" in the video below.

During a press conference tonight, FBI Special Agent Edward W. Reinhold said that they don't know what the suspect's motivation was behind the shooting.

Reinhold said they don't have any evidence that directly ties the shooter to an international terrorist organization and that there's no indication anyone else was involved.