During an unprovoked attack on four Queens, New York, police officers Thursday, Zale H. Thompson wielded a hatchet and charged the men in uniform. He struck two of the officials and was shot and killed by the two other law enforcement personnel.

With the suspect dead, investigators are now collecting information to determine what could have motivated Thompson to carry out such a brutal attack. Particular clues are seeming to point to radical Islam and recent extremist attacks in the West.

On the 32-year-old's Facebook page, his profile picture displays a black and white image of himself covered in a head and face scarf and brandishing a spear, sword and rifle. The page's banner is a quote from the Quran in Arabic that discusses judgment against people who have wandered astray.

While this is not a direct connection to ISIS or any other terrorist organization, these clues set investigators on alert to any links between Thompson and terrorist organizations.

Thompson, who was living in Queens before the attack, had a criminal record in California and had been discharged from the Navy for disorderly conduct, according to law enforcement officials.

The officers hurt in the attack are recovering in the hospital. Kenneth Healy, 25, was hit in the head with Thompson's hatchet and was listed in stable but critical condition at Jamaica Hospital Medical Center, according to the NYPD. Joseph Meeker, 24, was also injured in the arm during the attack but was listed in stable condition.

When the other two policemen opened fire on Thompson, a stray bullet struck a 29-year-old woman in the back. NYPD said she was recovering from surgery.

According to Police Commissioner Bill Bratton, Meeker was first hit in the arm and Thompson then turned and struck Healy in the head.

"As he continued his assault, the remaining two officers then fired on the armed suspect who fell to the ground dropping the hatchet," Bratton said. "The suspect was pronounced dead at the scene."