He played college football for the California Golden Bears and was selected by the Vikings in the fourth round of the 2021 NFL draft.

On film, he's a running back in space and in the return game who smoothly creates separation at the short to intermediate levels on a regular basis.."[14][15] The Minnesota Vikings selected Bynum in the fourth round (125th overall) of the 2021 NFL draft.

[23] On September 12, 2021, Bynum made his professional regular season debut in a 24–27 overtime loss at the Cincinnati Bengals and had two solo tackles.

[24] On December 8, 2021, Bynum earned his first career start at strong safety in place of Harrison Smith who was inactive in Week 9 due to COVID-19.

[27] He finished his rookie season in 2021 with a total of 28 combined tackles (20 solo), three pass deflections, one sack, and one interception in 14 games and three starts.

[28] On January 10, 2022, the Minnesota Vikings announced their decision to fire General Manager Rick Spielman and head coach Mike Zimmer after they finished the 2021 NFL season with an 8–9 record and did not qualify for the playoffs.

[29] On February 15, 2022, the Minnesota Vikings officially hired former Los Angeles Rams' offensive coordinator Kevin O'Connell as the new head coach.

On January 19, 2023, Minnesota Vikings' head coach Kevin O'Connell announced his decision to fire defensive coordinator Ed Donatell.

[34] Bynum entered training camp slated as the starting free safety, but had to compete against Lewis Cine to retain the role under new defensive coordinator Brian Flores.

[36] He started all 17 games and finished with a career-high 137 combined tackles (94 solo), nine pass deflections, three forced fumbles, two interceptions, and was credited with half a sack.

[39] He entered training camp slated as the starting free safety, ahead of Josh Metellus, Jay Ward, Lewis Cine , Bobby McCain, and Theo Jackson.

Head coach Kevin O'Connell retained Bynum and Harrison Smith as the starting safeties to begin the season.

He finished the 2024 NFL season with 96 combined tackles (54 solo), ten pass deflections, three interceptions, and two fumble recoveries while starting all 17 games.