Who was Mohammod Youssuf Abdulazeez, the man the FBI says killed 4 Marines in Tennessee?

Mohammod Youssuf Abdulazeez was the gunman who opened fire on two military centers in Chattanooga, Tenn., on Thursday, killing four Marines and injuring three other people before dying himself, the FBI said. Here is what we know about him so far:

He had lived in Tennessee for years

Abdulazeez was 24 and had been a longtime resident of the Chattanooga area.

He is believed to have been born in Kuwait, but he may have dual U.S.-Kuwaiti citizenship, according to a federal source who asked not to be named because of the ongoing investigation.

Abdulazeez attended Red Bank High School, northwest of Chattanooga, where he was on the wrestling team. He graduated in 2008.

He went on to University of Tennessee at Chattanooga, graduating in 2012.

He was smart and funny, a friend recalls

Photos of Mohammod Youssuf Abdulazeez in the Red Bank High School yearbook. (Chattanooga Times Free Press)

In high school, Abdulazeez was a sociable, smart student with a proclivity for science and math and a sharp sense of humor, said Terry Jones, an electrical engineer who lives in Knoxville, Tenn., and said he was one of Abdulazeez’s closest friends when they were teenagers.

“He had a really easy-to-get-along-with personality,” Jones, 25, told the Los Angeles Times in a phone interview. The two shared a favorite band -- System of a Down -- and an interest in media and filmmaking, and they took art classes together, Jones said. “Every art assignment, he would put a funny or humorous spin on it. He was kind of the funny guy in that class,” he said.

In the school yearbook, Abdulazeez’s senior quote read: “My name causes national security alerts. What does yours do?”

Jones and Abdulazeez largely lost touch after high school, but Jones said they checked in once in a while via Facebook chats, and nothing seemed unusual.

He was said to be a devoted Muslim with a caring mother

Abdulazeez was deeply religious, observing prayers five times a day and fasting during Ramadan, according to Jones, who never knew him to drink alcohol, smoke cigarettes or do drugs.

Jones played on the school’s tennis team with Abdulazeez’s younger sister, and the siblings’ mother regularly attended their games, he said: “She was just like any other mom. She was super nice, super caring.” Abdulazeez’s father often traveled for work, Jones said.

He majored in electrical engineering

Abdulazeez graduated in 2012 from the University of Tennessee at Chattanooga and has a degree in electrical engineering, the university confirmed.

He had an internship at the Tennessee Valley Authority “approximately five years ago,” spokesman Travis Brickey said. The Tennessee Valley Authority, a U.S.-owned corporation, produces electricity and provides flood control, navigation and land management for the Tennessee River system.

According to the federal source, Abdulazeez also worked for the city sewer department at some point.

He was arrested in April

Mohammod Youssuf Abdulazeez’s April mug shot. (Hamilton County Sheriff’s Office)

He was arrested April 20 in Hamilton County, which includes Chattanooga and Hixson, on a first-offense DUI charge, according to a record obtained by the Chattanooga Times Free Press. (The record misspells his name.)

Details from the last months of his life are still scare, but a federal law enforcement source said that during Thursday’s attacks, Abdulazeez was driving a gray Ford Mustang and had multiple weapons, including a long gun. It’s not clear where he got the weapons.

Times staff writers Richard A. Serrano and W.J. Hennigan contributed to this report.

READ MORE: Gunman kills four Marines at Tennessee military sites