TMZ Sports reported the news, noting a 13-year-old and 16-year-old were also shot in the attack but survived.
Police do not yet know the motive for the shooting and are still investigating.
Mathieu, a New Orleans native, explained why he offered to help:
"Young black children should not be dying from gun violence.
"Devante didn’t even have a chance to live his life before it was tragically taken away from him.
"My goal is to help stop the violence and help my community to show and empower children from my community that there is another way, one child at a time.
"I wanted to help the Bryant family because I am from the 7th Ward and I felt that pain. I have a seven-year-old son that lives in New Orleans and I couldn’t imagine something happening to him at that age. He is only two years younger than Devante."
"My heart goes out to the Bryant and Howard Family."
In addition to being from Louisiana, Mathieu played collegiately at LSU.
He is not the only notable athlete who attended LSU to make such a gesture.
In April, Shaquille O'Neal helped pay for the funeral of Keshon Batiste, an 11-year-old who died in a car crash in Louisiana. O'Neal also paid for the funeral of seven-year-old Jazmine Barnes in 2019.