Police tape and a makeshift memorial sit on the lawn outside an Armed Forces Career Center in Chattanooga, Tennessee, on Thursday. Reuters

Friends and family members publicly identified the first victim of Thursday's shooting at two Tennessee military facilities as Gunnery Sgt. Thomas Sullivan, a 40-year-old Marine from Massachusetts. Sullivan, who served in the Iraq War and received a Purple Heart award, was one of the four Marines killed in Chattanooga by suspected gunman Mohammod Youssuf Abdulazeez before he died in a shootout with police, CBS Boston affiliate WBZ reported Friday.

Sullivan joined the U.S. Marine Corps in September 1997 and studied criminal justice at American Military University, according to his Facebook page. A separate profile for the India Battery, 3rd Battalion, 12th Marines lists Sullivan as "one of our own." "There’s no Marine you would want that was better in combat than him,” his friend Josh Parnell, of Chicago, told the Oak Lawn Patch. "He’d been shot at so many times over the years and then for this to happen at home in the United States."

Authorities alleged Abdulazeez, 24, opened fire about 10:45 a.m. Thursday at a military recruitment center in a strip mall off Old Lee Highway Road. He fired about 30 times, then drove seven miles away to attack the Navy Operational Support Center and Marine Corps Reserve Center Chattanooga, where Sullivan was, military.com reported.

Sullivan grew up in Springfield, Massachusetts, where his family gathered Thursday after news of the shooting, the Republican reported. His father, Jerry; mother, Betty; sister, Dianne; and brother, Joe; showed reporters a military letter confirming Sullivan's death. His brother owns Nathan Bill's Bar and Restaurant, which posted a message on Facebook accompanied by photos showing the late Sullivan grinning in front of a tank and posing with a flag.

The post attracted more than 600 likes and dozens of comments. "He was our hero and he will never be forgotten. Please keep his family & friends in your thoughts & prayers," it read. "Thank you Tommy for protecting us."