Nico, 22, played for four seasons at Tulane before being picked up as an undrafted free agent. He had 319 tackles, 50.5 takedowns for a loss, seven sacks, seven forced fumbles, six fumble recoveries, five passes defended and four interceptions in 48 games for the Green Wave.
"Give thanks for the opportunity and belief in me," Marley tweeted Tuesday.
The Weston, Fla., native attended Cypress Bay High School. He left the Green Wave as the school's all-time leader in tackles for a loss. Marley earned 2016 All-American Athletic Conference first-team honors for his junior and senior campaigns. He was also named the Louisiana Sports Writers Association Co-Defensive Player of the Year.
While his grandpa was about 5-foot, 7-inches, Nico is 5-foot, 8-inches. Marley's dad, Rohan Marley, previously played football for the University of Miami and in the Canadian Football League.
Bob Marley died in 1981 at age 36.
Nico Marley tried out for the franchise last weekend during its annual rookie minicamp at the Inova Sports Performance Center at Redskins Park in Loudoun County, Va. The team also signed cornerback Tevin Homer and tight end Manassah Garner. Linebacker Khairi Fortt and tight end Wes Saxton were waived Tuesday, while cornerback Tharold Simon was released.