The suspect in the Florida high school shooting was charged with 17 counts of premeditated murder on Thursday, as the nation reels from yet another shooting that’s left a Florida town devastated.

More details have emerged on 19-year old Nikolas Cruz after he unloaded an AR-15 semiautomatic weapon on unsuspecting students and teachers at Marjory Stoneman Douglas High School in Parkland, Florida on Wednesday.

Cruz, who was expelled from the high school, was said to have a love for weapons, which he displayed on social media, according to ABC News.

President Trump tweeted on Thursday that there were many signs that Cruz was “mentally disturbed” and that his classmates knew he had issues. One of Trump’s first acts as president was to reverse an Obama-era rule that made it harder for people with mental illness to obtain firearms.

Buzzfeed News reported that last fall the FBI received warning of a possible school shooter when someone named Nikolas Cruz left a comment on a YouTube vlogger’s video saying, “I’m going to be a professional school shooter.”

Motives for the shooting still remain unclear.