Born and raised in Palmdale, California, Shead attended Highland High School and was a two-time All-Conference and All-CIF Southern Section defensive back.

[citation needed] Shead played college football at Portland State; he redshirted as a true freshman in 2007, and was named PSU Most Outstanding Defensive Back for the next four seasons.

[7] On November 27, 2013, Shead was promoted to the active roster from the practice squad,[8] and participated in Super Bowl XLVIII in February 2014, as the Seahawks defeated the Denver Broncos 43–8.

[9] After Seattle's loss in Super Bowl XLIX in February 2015, cornerback Byron Maxwell left for Philadelphia in free agency, leaving a starting position open opposite All-Pro CB Richard Sherman.

With Jeremy Lane and Tharold Simon still recovering from injuries, Shead was inserted as the second cornerback against Pittsburgh in place of Williams, and played well enough to earn the starting job full-time.

In Week 17, Shead recorded his first interception against the Arizona Cardinals, picking off quarterback Drew Stanton in the endzone.