Walter went undrafted in the 2019 NFL draft. He signed with the San Francisco 49ers on May 4, 2019, after a tryout with the team.[2][3][4] He was waived by the 49ers on August 31, 2019.[5]
On September 18, 2019, Walter was signed to the practice squad of the New York Giants.[6] Following injuries to starting running back Saquon Barkley and backup Wayne Gallman, Walter was promoted to the 53-man roster on October 10, 2019, but then waived the next day.[7]
On November 22, 2019, Walter was drafted by the Dallas Renegades in the 2020 XFL Supplemental Draft.[8] He had his contract terminated when the league suspended operations on April 10, 2020.[9] He returned a 97-yard kickoff for a touchdown, the longest in XFL franchise history.
On September 23, 2020, Walter was signed to the 49ers' practice squad.[10] He was elevated to the active roster on November 5 for the team's week 9 game against the Green Bay Packers, and reverted to the practice squad after the game.[11] He was promoted to the active roster on November 11, 2020.[12] He was placed on the reserve/COVID-19 list by the team on December 17, 2020,[13] and activated on December 28.[14] On February 8, 2021, the 49ers signed him to a one-year contract extension.[15] He was waived on May 12, 2021.[16]
Walter was claimed off waivers by the New York Jets on May 13, 2021.[17] He was waived/injured on August 17, 2021, and placed on injured reserve.[18] He was released on August 26. Walter was re-signed to the practice squad on October 5, 2021.[19] Walter played his first game for the Jets against the Houston Texans on November 28, 2021, and rushed for 38 yards on 9 carries, including his first NFL touchdown.[20] On December 4, 2021, Walter was elevated from the practice squad for the game against the Philadelphia Eagles.[21] On December 7, 2021, Walter was promoted to the active roster.[22] He was waived on May 6, 2022.
On July 29, 2022, Walter signed with the Las Vegas Raiders.[23] A few days later, in the 2022 Pro Football Hall of Fame game, Walter scored a touchdown against the Jacksonville Jaguars.[24] On August 30, 2022, Walter was waived by the Raiders[25] and then signed to the practice squad the next day.[26] He signed a reserve/future contract on January 9, 2023.[27] He was placed on injured reserve on August 3, 2023.