Jacksonville police officers block the perimeter of the scene of a mass shooting on Saturday, in Jacksonville, Fla. John Raoux/Associated Press

The man who fatally shot three Black people in a racist attack at a Dollar General in Jacksonville, Fla., was identified Sunday as Ryan Palmeter, a 21-year-old white man.

Palmeter penned multiple manifestos that were full of racist ramblings, Sheriff T.K. Waters said.

“They were, quite frankly, writings of a madman,” Waters said Sunday on “Good Morning America.” “They [included] the rather liberal use of the N-word, several times. It was clear that his crimes were motivated by wanting to shoot Black people.”

Palmeter lived with his parents in Orange Park, Florida, about 10 miles south of where he opened fire.

The three victims were also identified Sunday as Angela Michelle Carr, 52; Anolt Joseph “A.J.” Laguerre Jr., 19; and Jarrald De’Shaun Gallion, 29. Waters laid out a chilling timeline of the shooting.

Palmeter first approached Edward Waters University, a historically Black university, at 12:48 p.m. Security at the school noticed him seven minutes later, and Palmeter pulled out of the school’s parking lot at 12:57 p.m., followed one minute later by security.

“He had an opportunity to do violence at EWU; he did not,” Waters said, adding that he believes Palmeter simply used the parking lot to put on his mask and bulletproof vest.

Palmeter traveled to the Dollar General and fired 11 bullets at Carr at 1:08 p.m. as she was sitting in her black Kia outside the store. The gunfire was captured on Dollar General security video.

The gunman then entered the store and fatally shot Laguerre. At the same time, several people were seen on video fleeing out the rear door of the store. Palmeter followed them out and opened fire indiscriminately but did not strike anyone, according to Waters.

At 1:10 p.m., Gallion entered the store alongside his girlfriend. Three minutes later, Palmeter shot and killed Gallion. He chased Gallion’s girlfriend through the store, but she escaped.

Police officers arrived on the scene at 1:19 p.m., Waters said. While they were clearing a hallway searching for the shooter, they heard a single gunshot. Investigators believe that is when Palmeter killed himself.

One minute before his death, Palmeter had texted his father and told him to enter his bedroom. In the room, the father found a suicide note and a last will and testament on his son’s laptop.

“I urge us all not to look for sense in a senseless act of violence,” Waters said Sunday. While he described Palmeter as a “madman,” he also told reporters the gunman “knew what he was doing.”

The attacker used two guns, a Glock handgun and a semi-automatic rifle, Waters said. Swastikas were painted on the rifle.

Both weapons were purchased legally at gun stores in Florida. Palmeter bought the Glock in April and the rifle in June, according to Waters.

“There was no flag that could’ve come up to stop him from purchasing those guns,” the sheriff said. “The story is always about guns. The people are bad. This guy is a bad guy.”