WASHINGTON, DC -- The Garland police officer who shot two Islamic State-inspired attackers during the assault on the Curtis Culwell Center in May 2015 was awarded the Public Safety Officer Medal of Valor by President Obama on Monday.

Officer Gregory Stevens was one of 13 police officers to receive the honor in the ceremony.

"To a person, each of these honorees acted without regard to their own safety," Obama said in a ceremony in the East Room of the White House evoking the formality of a military Medal of Honor presentation. "We're so grateful they were there — some off duty, others on duty, and all rising above and beyond the call of duty."

The ceremony, held during National Police Week, came shortly after Obama signed into law two police-related bills renewing a bulletproof vest grant program and allowing free U.S. Capitol flags for the families of fallen first responders.

Obama called on Americans to support law enforcement officers with deeds as well as words, and thanked their families for the burden they also face.

US President Barack Obama (R) awards the Medal of Valor to Officer Gregory Stevens, Garland, Texas, for exchanging gunfire at close range and subduing two heavily-armed assailants, thereby preventing a mass shooting, during a ceremony at the White House in Washington, DC, May 16, 2016. Obama awarded the nation's highest honor for law enforcement to 13 police officers May 16, recognizing officers who put themselves in harm's way, one fatally, to protect citizens. / AFP / Jim Watson (Photo credit should read JIM WATSON/AFP/Getty Images)
US President Barack Obama (R) awards the Medal of Valor to Officer Gregory Stevens, Garland, Texas, for exchanging gunfire at close range and subduing two heavily-armed assailants, thereby preventing a mass shooting, during a ceremony at the White House in Washington, DC, May 16, 2016. Obama awarded the nation's highest honor for law enforcement to 13 police officers May 16, recognizing officers who put themselves in harm's way, one fatally, to protect citizens. / AFP / Jim Watson (Photo credit should read JIM WATSON/AFP/Getty Images)

"We know that you wait up late and you’re worried and you're counting down the minutes until your loved one walks through the door safe after a long shift. We know it never gets easier, and we thank you for that," Obama said. "And of course we honor those who didn't come home, including one hero we honor posthumously today."

Officer Stevens received the award “for demonstrating extraordinary courage to save lives,” according to a statement the White House released Friday. Established by President Bill Clinton in 2000 and officially recognized by Congress in 2001, the Medal of Valor is the nation's highest honor for law enforcement.

The attack happened during a “Draw the Prophet” event, put on by the American Freedom Defense Initiative. Security around the building had been ramped up because of the nature of the event.

Two men, Elton Simpson and Nadir Soofi, drove from Phoenix, Ariz. to Garland, pulled up to the entrance drive of the facility, got out of their car and started shooting.

A Garland ISD officer was injured in the gunfire from Simpson and Soofi.

A single Garland police officer, Gregory Stevens, opened fire, subduing both men, and preventing them from attacking the event.

A third man has been convicted in Phoenix of helping Simpson and Soofi set the attack up.

The shooting is believed to be the first IS-inspired attack in the U.S.

Monday's ceremony was the first time Officer Stevens has appeared publicly since the attack.