Mohammod Youssof Abdulazeez has been identified by the FBI as the gunman who fatally shot four Marines and wounded a police officer on Thursday in shootings at two military recruiting and training centers in Chattanooga, Tennessee.

Abdulazeez, 24, is also dead, the FBI says.

At least two others were injured, including one in critical condition. The officer is in stable condition. The shootings happened at separate military reserve centers on Lee Highway and Amnicola Highway.

Here’s what we know so far:

1. He Was a Naturalized U.S. Citizen Originally From Kuwait

NBC News reports that Abdulazeez is a naturalized U.S. citizen originally from Kuwait. His family is Jordanian.He came to the United States in 1996 with his parents.

Abdulazeez visited Jordan for about seven months last year, according to the New York Times.

He lived in Hixson, Tennessee, which is a community in Chattanooga, in a middle-class Muslim family.

The FBI was searching the neighborhood where his family lives:

Two women were seen being removed from the home in handcuffs, but neither was arrested.

He was arrested on April 21, 2015 for driving under the influence in Hamilton County, Tennessee, according to the Chattanoogan.com.

Police have not yet released a motive for why the gunman targeted the two military facilities and military personnel. Authorities said he did not work at the military centers. The shooting is being investigated as “national security” case and the FBI is leading the probe.

Police believe he acted alone and they are not actively searching for another shooter.

2. He Wasn’t on Terror Watch Lists & It’s Not Yet Known if He Had Ties to Islamic Terrorists

Abdulazeez was not being watched by the FBI or on any terror watchlists prior to the shooting, CBS News reports.

The FBI is now trying to determine if he has any ties to terror groups, if he was inspired by organizations like ISIS and if he had any accomplices. The Justice Department said it is a “national security” investigation.

The chairman of the House Committee on Homeland Security, Rep. Mike McCaul, R-Texas, said the case is an “open terrorism investigation,” and he believes, based on his experience, that it was inspired by ISIS.

But federal authorities said at a press conference that there is no indication yet that the attack was ISIS-inspired.

Several ISIS-affiliated Twitter accounts tweeted about the shooting, praising Abdulazeez.

An ISIS-related account tweeted “O American dogs soon YOU will see the wonders,” and used #Chattanooga.

The account has tweeted out other references to Chattanooga:

The account also has several anti-American and pro-ISIS tweets.

ISIS often uses social media to recruit supporters and to distribute its propaganda videos, including disturbing executions. They also have told their followers to carry out attacks in their name across the world, including in the United States. Terrorism experts say it’s not likely ISIS fighters would try to come to the United States, but that they would try to inspire Americans to carry out attacks here.

The terror organization had called for an increase in terror attacks at the end of Ramadan. The holiday comes to a close on Friday.

3. He Was a Recent College Grad & Electrical Engineer Who Was Trained as an MMA Fighter

Abdulazeez attended Red Bank High School in Tennessee. According to the Chattanooga Times Free Press, his high school yearbook quote was, “My name causes national security alerts. What does yours do?”

Senior quote: "My name causes national security alerts. What does yours do?” http://t.co/cL3wXBf2qj pic.twitter.com/QfhV5PcJHQ — Times Free Press (@TimesFreePress) July 16, 2015

“He was an unbelievable nice person,” a high school classmate, Ryan Smith, told the Times Free press. “He was honestly one of the funniest guys I’ve ever met.”

Smith said Abdulazeez was also religious.

Abdulazeez graduated from the University of Tennessee-Chattanooga in 2012, according to posts on his mother’s Facebook page and a resume posted on Indeed.com.

He graduated with a degree in electrical engineering. He worked from April 2009 to April 2010 as an intern with the Tennessee Valley Authority, a federally owned corporation that provides electricity to 9 million people in the southeast. He also had internships at Mohawk Industries and Global Trade Express.

The Chattanooga Times Free Press reports that his father is a city employee in the public works department.

CBS News incorrectly reported that he was an employee of the city of Chattanooga:

False reports the suspect is a City of #CHA employee. Please be mindful during this difficult time of sending inaccurate reports. @CBSNews — City of Chattanooga (@Chattanooga_gov) July 16, 2015

Abdulazeez was a high school wrestler and trained as a mixed martial arts fighter.

He fought in at least one match, in 2009.

It’s not clear how many fights he had, but a video of one of the fights was posted online and promoted on an MMA message board.

4. He Wrote 2 Blog Posts About Islam Days Before the Attack

Abdulazeez made wrote two blog posts on a recently created website just days before the attack. Both posts were published on July 13, 2015.

In the first posted, title “A Prison Called Dunya,” he wrote:

I would imagine that any sane person would devote their time to mastering the information on the study guide and stay patient with their studies, only giving time for the other things around to keep themselves focused on passing the exam. They would do this because they know and have been told that they will be rewarded with pleasures that they have never seen.

He also said in that post that life is “nothing more than a test of our faith and patience,” adding:

It was designed to separate the inhabitants of Paradise from the inhabitants of Hellfire, and to rank amongst them the best of the best and worst of the worst. Don’t let the society we live in deviate you from the task at hand. Take your study guide, the Quran and Sunnah, with strength and faith, and be firm as you live your short life in this prison called Dunya. Allah (SWT) says live for this life and the hereafter according to their length. Rasulullah says the life on this world compared to the hereafter is like a drop compared to an ocean. Brothers and sisters don’t be fooled by your desires, this life is short and bitter and the opportunity to submit to allah may pass you by. Take his word as your light and code and do not let other prisoners, whether they are so called “Scholars” or even your family members, divert you from the truth. If you make the intention to follow allahs way 100 % and put your desires to the side, allah will guide you to what is right.

The second post was called “Understanding Islam: The Story of the Three Blind Men.” He wrote about the Prophet’s Sahaba, or companions:

We often talk about the Sahaba (RA) and their Ibada. We talk about their worshiping at night, making thikr, reading quran, fasting, sala. But did you ever notice that in one certain period towards the end of the lives of the Sahaba (RA), almost every one of the Sahaba (RA) was a political leader or an army general? Every one of them fought Jihad for the sake of Allah. So this picture that you have in your mind that the Sahaba (RA) were people being like priests living in monasteries is not true. All of them towards the end of the lives were either a mayor of a town, governor of a state, or leader of an army at the frontlines. The Sahaba (RA) were very involved in establishing Islam in the world. Their mission was to establish Islam and live it. … We ask Allah to make us follow their path. To give us a complete understanding of the message of Islam, and the strength the live by this knowledge, and to know what role we need to play to establish Islam in the world.

5. He Opened Fire From His Mustang at the Recruiting Center & Then Gunned Down the Marines at Another Facility

Abdulazeez’s shooting spree began at at a National Guard recruiting center on Lee Highway.

A woman who worked at a restaurant next to the recruiting office on Lee Highway told CNN she saw the shooting.

“I looked out of our window and I seen the guy in his car, a silver Mustang, drop top, a white guy and he had a high-powered rifle and was just firing shots into the Air Force, Navy and Marines office,” Gina Mule told CNN. “I don’t even know how many shots he fired, but it was a lot. … After he got done opening fire, he pulled out really quick.”

He then drove to to another military facility on Amnicola Highway, where he killed the four Marines.

The two military facilities are about eight miles apart.

Abdulazeez was chased by police officers after the shootings and engaged in a shootout with them. One of the officers was shot in the leg during that encounter.

Police Chief Fred Fletcher said officers “actively and enthusiastically” engaged with Abdulazeez on Amnicola Highway, where he was killed by Chattanooga police officers.

Abdulazeez was armed with two long guns and a handgun, the FBI said.

Read more coverage about the shooting and investigation at the link below: