As a sophomore, he was switched to free safety and received All-East Texas Newcomer of the Year honors.[3]
As a junior, he was named All-East Texas Defensive Player of the Year and first-team All-district, while helping his team reach the state semifinals.
As a senior, he had 142 tackles (14 for loss), 5 sacks, 5 interceptions, 13 pass breakups, 4 forced fumbles and 2 fumble recoveries. He received Defensive MVP of District 9-3A II, first-team All-district, first-team All-State by the Associated Press, first-team All-State by the Texas Sports Writers Association and first-team All-USA Texas by USA Today honors.
Overshown accepted a football scholarship from the University of Texas. He played as a backup safety during his first two years, appearing in 17 games, while registering 19 tackles, 2 sacks and one interception.
As a sophomore in 2019, he missed four games due to a back injury, that he suffered in the seventh game against the University of Kansas.
Prior to his junior season in 2020, he switched to weakside linebacker.[8] He started all 10 games, recording 60 tackles, one sack and two interceptions.[9] He was named the Defensive MVP of the 2020 Alamo Bowl, after making 6 tackles (0.5 for loss), one interception, 2 quarterback hurries and one fumble recovery.
Overshown returned to Texas for his senior year, rather than enter the 2021 NFL draft.[10] He started 10 games (missed one contest with a toe injury), while recording 74 tackles (led the team), 5.5 tackles for loss, 2 sacks, 2 fumble recoveries, 2 pass breakups and one blocked kick. He had 9 tackles (0.5 tackles for loss) against Texas Tech University. He made 10 tackles with a career-high eight solo stops and one fumble recovery against Texas Christian University.
As a super senior in 2022, he appeared in 12 games (11 starts), posting career-highs with 96 tackles (10 for loss), 4 sacks and five pass breakups. He received first-team All-Big 12 honors. He had 9 tackles (1.5 for loss) against Kansas State University. He made 11 tackles (half a tackle for loss) and half a sack against Texas Christian University. He had 14 tackles (2 for loss), one sack and 2 pass breakups against Baylor University.[3]
Overshown was selected by the Dallas Cowboys in the third round (90th overall) of the 2023 NFL draft.[13] During the second preseason game against the Seattle Seahawks, Overshown was carted off the field after sustaining an injury.[14] It was revealed after the game he had a torn ACL, ending his season.[15]
Overshown made his NFL debut in Week 1 of the 2024 season against the Browns and recorded a sack.[16] He scored his first NFL touchdown in a Week 13 game on an interception return against the New York Giants on Thanksgiving Day. In 13 games (12 starts) for the Cowboys, he logged one interception, one forced fumble, one fumble recovery, five sacks, and 90 combined tackles. On December 10, 2024, it was announced that Overshown would miss the remainder of the season and part of the 2025 season after suffering a torn ACL, MCL, and PCL in Week 14 against the Cincinnati Bengals.[17]