The suspect put on a bulletproof vest and mask while still on campus, and then went to the nearby Dollar General, Jacksonville Sheriff T.K. Waters told CNN’s Jim Acosta. Armed with an AR-15 style rifle and a handgun, the gunman opened fire outside the store and then again inside, fatally shooting the three victims before killing himself, according to Waters.

The three victims killed, two males and one female, were all Black, the sheriff said.

The university, which is in a historically Black neighborhood, went into lockdown Saturday and students living on campus were told to stay in their residence halls.

The attack clearly targeted Black people, Waters said. The suspect used racial slurs and left behind writings to his parents, the media and federal agents outlining his “disgusting ideology of hate,” the sheriff told reporters.

“This shooting was racially motivated, and he hated Black people,” Waters said at a news conference Saturday evening.

The shooter did not appear to know the victims and it is believed he acted alone, he said.

“This is a dark day in Jacksonville’s history,” the sheriff said. “Any loss of life is tragic, but the hate that motivated the shooter’s killing spree adds an additional layer of heartbreak.”

The FBI has launched a federal civil rights investigation into the shooting and “will pursue this incident as a hate crime,” said Sherri Onks, special agent in charge of the FBI’s Jacksonville office.

The Jacksonville attack was one of several shootings reported in the US over two days, including one near a parade in Massachusetts and another at a high school football game in Oklahoma, underscoring the everyday presence of gun violence in American life.

There have been at least 472 mass shootings in the US so far in 2023, according to the Gun Violence Archive, which, like CNN, defines a mass shooting as one in which four or more people are wounded or killed, not including the shooter. It is almost two mass shootings for each day of the year so far. The nation surpassed the 400 mark in July, the earliest month such a high number has been recorded since 2013, the group said.

The shooter, who lived in Clay County with his parents, left his home around 11:39 a.m. Saturday and headed to Jacksonville in neighboring Duval County, Waters told CNN.

At 1:18 p.m., the gunman texted his father and told him to check his computer, according to Waters, who did not provide details on what was on the computer.

At 1:53 p.m., the father called the Clay County Sheriff’s office, the sheriff said.

“By that time, he had began his shooting spree inside the Dollar General,” Waters said of the gunman.

Officers responded to the scene as the gunman was exiting the building. The gunman saw the officers, retreated into an office inside the building and shot himself, Waters said.

Photos of the weapons the gunman had were shown by authorities, including one firearm with swastikas drawn on it. While it remains under investigation whether the gunman purchased the guns legally, the sheriff said they did not belong to the parents.

“Those were not his parents’ guns,” Waters told reporters Saturday. “I can’t say that he owned them but I know his parents didn’t – his parents didn’t want them in their house.”

“The suspect’s family, they didn’t do this. They’re not responsible for this. This is his decision, his decision alone,” the sheriff later told CNN.