An American citizen’s use of a military-style semi-automatic weapon to carry out a mass murder on U.S. soil thrust President Donald Trump into a somber spotlight on Thursday, and he sent a clear signal he views the incident as about mental health, not guns.

The president offered his condolences to the loved ones of the 17 people law enforcement officials say 19-year-old Nikolas Cruz shot dead at Marjory Stoneman Douglas High School in Parkland, Florida. He also spoke in the same measured tone he and his predecessor, Barack Obama, have used following shooters’ murderous rampages.

“We are all joined together as one American family, and your suffering is our burden, also,” Trump said. “No child, no teacher, should ever be in danger in an American school.”

Top administration officials responded in the wake of the shooting by offering thoughts and prayers. But by Thursday morning, senior officials — including Trump and his attorney general — seized on mental health issues as to blame for the massacre, not Cruz’s ability to purchase the AR-15 assault rifle law enforcement officials say he was armed with when he entered the school.

Watch: Trump Sends Condolences to Florida Shooting Victims and Families