Richardson signed with the New Orleans Saints as an undrafted rookie free agent in 2015. Richardson started 2015 as a starting defensive end for the Saints. In the Saints' Week 15 matchup against the Jacksonville Jaguars, Richardson recorded his first career interception. Saints cornerback Delvin Breaux tipped a ball thrown by Jaguar quarterback Blake Bortles and it flew through the air, allowing Richardson to catch it. On September 3, 2016, he was waived by the Saints.[3] He was then signed to the Saints' practice squad. On September 14, 2016, he was released from their practice squad.[4]
Washington Redskins
On September 19, 2016, Richardson was signed to the Washington Redskins' practice squad.[5] He was released on October 19, 2016.[6]
Kansas City Chiefs
Richardson was signed to the Kansas City Chiefs practice squad on October 26, 2016. He was released on November 9, 2016.
Denver Broncos
On February 24, 2017, Richardson signed with the Broncos.[7] On May 3, 2017, Richardson was waived by the Broncos.[8]
New York Giants
On August 15, 2017, Richardson signed with the New York Giants.[9] He was waived on September 2, 2017.[10]
In October 2019, Richardson was among the Tampa Bay Vipers' open-round choices in the 2020 XFL Draft.[14] He had his contract terminated when the league suspended operations on April 10, 2020.[15]