The FBI is investigating last week's shooting in Chattanooga, Tenn., as an act of a "homegrown violent extremist," an agent said at a press conference Wednesday.

However, it's too soon to tell if 24-year-old Muhammad Youssef Abdulazeez had been "radicalized" before the attacks that left four Marines and one sailor dead, FBI Special Agent Eric Reinhold told reporters.

According to Reinhold, Abdulazeez was shot at by a service member after he crashed through the gates of the military facility. Abdulazeez then went into the building, shot a service member and continued shooting before going out back and shooting two more people. Police eventually opened fire on Abdulazeez, killing him. He killed one person inside and four people outside, Reinhold said.

"We are committed to working with our partners in law enforcement ... to investigate, review and guard against future vulnerabilities," Rear Adm. Mary Jackson, commander of Navy Region Southeast, said at the press conference.

"Throughout our nation's history, sailors and Marines have served overseas, in harm's way, and have experienced the deep and lasting pain of combat loss. Today, here at home, we feel that pain," Jackson said, before praising the Chattanooga community for rallying "during this difficult time."

The shooter took the lives of Gunnery Sgt. Thomas Sullivan, Staff Sgt. David Wyatt, Sgt. Carson Holmquist, Lance Cpl. Squire Wells and Petty Officer 2nd Class Randall Smith.

Abdulazeez was born in Kuwait to Jordanian parents, but was a naturalized American citizen who lived in the Chattanooga area most of his life.