Johnson attended Tumwater High School, where he practiced football, basketball and baseball. He received All-league honors three years in a row in football. As a senior, he collected 53 tackles, two interceptions and one fumble recovery while helping his team reach the Class 2A state semifinals. He was named second-team 2A All-Evergreen League, after missing five games because of a high ankle sprain. He also helped his school reach the 2A District IV basketball tournament and win the District IV baseball championship.
College career
Johnson accepted a football scholarship from Eastern Washington University. As a redshirt freshman, he posted 11 starts, 83 tackles, five tackles for loss and four interceptions. He made 10 tackles against Texas Tech University. He had two interceptions against Western Washington University. He made 12 tackles against the University of Northern Colorado. As a sophomore, he tallied 101 tackles and six interceptions, the latter leading the conference. He had 16 tackles against Weber State University. He had four interceptions against Portland State University, tying a single-game conference record. He had 14 tackles against the University of Montana and Montana State University. As a junior, he helped the team win the NCAA Division I FCSNational Championship, while registering 105 tackles, five interceptions, eight passes defended, two forced fumbles and one fumble recovery. He also contributed to the defense being ranked number one nationally with 26 interceptions and 47 turnovers forced. He had two interceptions against the University of Montana. He was named a team co-captain along with his twin brother Zach. As a senior, he missed the final four games with an injured shoulder, recording 52 tackles, eight tackles for loss, two interceptions, 1.5 sacks, one quarterback hurry, two forced fumbles and earned All-Big Sky conference honors for the second straight season. He had four tackles and one sack against the University of Washington. He injured his shoulder against the University of South Dakota, but still managed to intercept one pass and then had back-to-back games with nine tackles /against the University of Montana and Montana State University, while fighting through the injury. He finished with 45 starts, 341 tackles, 22 tackles for loss, 30 passes defended, 17 interceptions and six forced fumbles.
