A new petition asks the White House to honor Howell's sacrifice with a military burial.
The petition, directed at the White House, was created by someone identified only by the initials L.K. on Wednesday.
By 2:20 p.m. Thursday, the petition reached more than 3,600 signatures, but it's still a long way from the 100,000 needed by May 31 to elicit a response from the White House.
The shooter rushed inside a classroom Tuesday and opened fired just as Howell and about 30 other students were listening to final presentations in an anthropology class.
Charlotte-Mecklenburg Police Department Chief Kerr Putney said 21-year-old Howell ran at the gunman and knocked him off his feet — something that eventually helped police arrest the suspect.
"He's an athletically built young man and he took the fight to the assailant," Putney said. "Unfortunately, he had to give his life to do so but he saved lives doing so."
Howell's aunt said she was not surprised when she learned of her nephew's actions during the attack.
"He did such a heroic thing," Moylan said. "He was everybody's protector. You felt safe when you were with Riley."
Howell grew up taking care of his three younger siblings on his family's farm in Waynesville, North Carolina. He spent time working out with first responders and dreamed of serving in the military or firefighting.
In a statement, Howell's family said he always stood up for what he believed and didn't hesitate to help those in need.
"His faith was strong and he knew what he had to do when people needed him most," the family said in a statement Wednesday. "He was always the guy you could count on and he delivered."
His aunt said he had put off signing up for the military to go to college. After graduating from Roberson High School in Asheville, North Carolina, he briefly attended Asheville-Buncombe Technical Community College before transferring to UNCC.
This was his first year at the university and, as were many other students, Howell was attending the term's final day of classes on Tuesday.
Howell and 19-year-old Ellis Parlier, of Midland, were both killed in the shooting while four others were injured.
The university has identified the injured as Rami Al-Ramadhan, 20, of Saihat, Saudi Arabia; Sean DeHart, 20, and Drew Pescaro, 19, of Apex, North Carolina and Emily Houpt, 23, of Charlotte.
CNN Wire contributed to this report.