Justin was deployed to Afghanistan where he served as a medic, and returned home safely after completing his tour. Upon his return to the States, he developed a severe drug addiction.

Justin was the first Walker sibling to learn of his late father’s affair with actress Holly Harper—a revelation that shook the entire Walker family to the core. Later, Justin met Holly’s daughter Rebecca, eventually discovering that Rebecca could in fact be Justin’s illegitimate sister. Despite the shock, Justin and Rebecca developed a close friendship.

When the Army again called Justin back to service—this time for Iraq—Justin went on a binge and overdosed. Justin entered rehab and cleaned himself up, but his fateful return to active duty kept looming. After a bittersweet farewell, Justin reported for duty.

After being injured in Afghanistan Justin returned home and developed an even stronger friendship with Rebecca who helped nurse him back to health. Later, it was revealed that Rebecca wasn’t Justin’s sister at all, though they remained close friends. Eventually Justin and Rebecca fell in love and began a romantic relationship.

When Justin’s brother-in-law, Senator Robert McCallister, had a heart attack, Justin realized his calling: he wanted to become a doctor. Rebecca was thrilled for Justin when he was accepted into an accelerated joint Bachelors/M.D. program not far from Los Angeles.

Shortly after being accepted to medical school Justin proposed to Rebecca and she happily accepted. Now Justin is embarking on a whole new chapter of his life as he begins medical school, planning his wedding and preparing to call father’s ex-mistress “mom.”