Justin was Victor Kiriakis' nephew and came to Salem in 1987. Both of Justin's parents were dead, and he and Victor were the only family each other had. Justin enjoyed the high life, and the ladies, and had a brief fling with Angelica Deveraux when he first came to town. Justin soon met and fell in love with Adrienne Johnson. Adrienne was a poor girl, and Justin hid his identity from her because his uncle Victor was involved in a project Adrienne was against. Adrienne and Justin fell in love, but Victor, who didn't approve of their relationship told Adrienne that Justin was his nephew. Adrienne was hurt, but was still in love with Justin.
In 1987, Justin and Adrienne married in Greece, yet once they returned to Salem things became rocky. She hated his illegal ties with the Kiriakis business and that stress caused her to miscarry when she became pregnant with their child. Justin accused her of purposely losing their child and the two grew further apart. Eventually, Justin chose to make their marriage work and moved out of the Kiriakis Mansion - leaving behind is uncle as well as their illegal dealings. Unfortunately for the couple, when Victor was shot Justin returned to the mansion to oversee the Kiriakis Empire. Adrienne, however, didn't return with him. Justin turned to Angelica Deveraux when Adrienne rejected him, and she became pregnant with his child.
Adrienne began having an affair with the Kiriakis stable hand Emilio Ramirez. Justin was furious at this and arranged for Emilio to be killed in an accident, but Justin ended up getting caught in his own trap and was paralyzed. This accident caused Adrienne to return to Justin, and they made up. In time Justin regained the use of his legs, but was impotent as a result of the accident, leading to more tension between the couple. Angelica, now married to Neil Curtis, contemplated telling Justin he was the father of her son Alexander, but decided against it for the time being. Later Justin was almost killed when Emilio tried to get revenge on him by cutting the brakes in his car.
Eventually Justin and Adrienne learned that Angelica's son Alexander was his son, but they didn't split up. Justin and Adrienne moved out of the Kiriakis mansion when Justin learned that his uncle Victor was drugging him, causing his impotency. In an attempt to get back at his uncle Justin hired a hooker name Yvette DuPrés to seduce his uncle and con him into believing she was a wealthy baroness. Victor eventually learned the truth and was furious with him. Angelica then moved in with Victor and planned to marry him knowing that it would kill Justin to have his son under Victor's roof. Justin refused to allow that happen and stopped the wedding. Justin then set Angelica up in a lavish penthouse apartment. Fearing she was losing Justin Adrienne, under the advice of Victor, allowed Justin to believe she was pregnant. When Angelica learned the truth and exposed Adrienne, both Justin and Adrienne agreed to get a divorce.
Soon the former spouses where in competition when both Adrienne and Justin decided to open construction companies. They also began dating again, which made Angelica angry. Angelica bribed one of Adrienne's men to blow up a building her company was working on. As a result, Adrienne became trapped in a pit. Justin managed to rescue Adrienne and he claimed that he was responsible for the blast. However, when Angelica knew she would be discovered sooner or later, she fled town. Angelica's plane crashed and she and little Alexander were presumed dead. In reality, they had boarded another flight. Justin and Adrienne grew closer because of the incident and Victor disowned him. Eventually they remarried on June 1, 1990.
Upon returning from their honeymoon, Justin and Adrienne took pity on Angelica's wacky housekeeper, J.J. Bagwood, and hired her as their own. Coincidentally, Justin and Adrienne were having problems conceiving, so when J.J. became pregnant she offered to give her twins to them. After the baby's births on September 19, 1990, their biological father, Stanley, came forward to claim them. Like their father, J.J. also had doubts about giving up the twins, but they soon realized that Justin and Adrienne could give them a better life. After handing over custody, both J.J. and Stanley left Salem. A short time later, Adrienne became pregnant and eventually gave birth to a health baby boy, Jackson. Needing a fresh start, they moved to Texas with their children and started the A.J. Construction Company. Before leaving Justin, Adrienne, and Victor all reconciled and Johnny Corelli reunited Justin with Alexander, the son who he believed had died.
Although never shown on-screen, Justin returned to Salem in 2007 with Adrienne and his sons. While she was busy helping her family deal with the fallout of her recently resurrected brother Steve's brainwashing, he tried to reestablish roots, but soon found it hard to readjust to life back in Salem. In January 2008, Justin accepted a job in Dubai and moved his entire family there.
In August of 2009, Justin, now a lawyer, returned to Salem (and this time he was seen on screen). Victor’s godson, Dr. Daniel Jonas, had been falsely accused of attempted murder so Victor sent for his nephew to provide Daniel legal representation. Justin quickly returned from Dubai and got to work. His first victory on the case was when he thwarted Charles Woods, Salem’s new D.A. Woods attempted to railroad Daniel, who had just gotten out on bail, and have him sent back to jail for a “violation,” but Justin saved the day with his sharp skills.
Aside from the case, Justin was thrilled to see his family and friends in Salem. While catching up with Victor, Bo and Hope, he mentioned that Adrienne and his children were fine, although Jackson was the only one of their sons still living at home with them. Later, however, when Justin talked with Hope in private, he admitted that he and Adrienne were having marital problems. Part of their problems stemmed from them not adjusting well to the impending “Empty Nest Syndrome” once Jackson leaves home. Soon after, Justin received divorce papers from Adrianne.
Justin found comfort with Hope, who was also separated from Bo. However, she did not return his feelings. In March of 2010, Hope called Adrianne to Salem, under the false pretense that Justin was in trouble, in hopes that the two would reconcile. The two butted heads and once Adrienne realized that Justin had developed some feelings for Hope, Adrienne was furious. But, as Bo and Hope reconciled, Justin and Adrienne began growing closer as well. The two went to Vegas to get remarried in April of 2011 and returned to Salem to continue their life together.
Their son Jackson, now going by Sonny, returned to Salem in June of 2011. He wanted to return to Salem to tell the members of his extended family that he was gay. Justin and Adrienne had known for years, but Sonny wanted to tell Victor and the rest of the family. All of his relatives were supportive. Justin was happy for Sonny when Sonny and Will began dating.
Justin assumed a larger role with Titan, heading up their legal division. He garnered a reputation as a good lawyer outside of business as well. E.J. came to Justin with a job offer -- to help E.J. take over the legal aspects of the DiMera Empire. The two men orchestrated an unlikely take-over thanks to a share holder's meeting. Victor and Adrienne were concerned that this would make Justin one of Stefano's targets. But, Justin was confident in his work.
E.J. came to Justin for help again when Sami was arrested for shooting Detective Joe Bernardi. Sami told Justin the truth, that Bernardi was standing over Rafe with a razor when she shot Bernardi in the back before even seeing his face. But neither Sami nor E.J. told Justin that they knew Bernardi was a dirty cop. They didn't tell Justin because it would expose how they knew that Bernardi was dirty -- Sami went to Stefano and asked him to remove some incriminating evidence against Will. Stefano agreed and had Bernardi remove the evidence. Sami tried to get the evidence from Bernardi, even attacking him, but she was unsuccessful.
However, Chad video taped Sami attacking Bernardi, thinking that Sami was just humorously acting out. Chad shared the video with Sonny, who shared it with Adrienne. When E.J. learned about the video, he kept the news from Justin.
Adrienne did not like Will's family and did not like that by dating Will, Sonny was associated with them as well. Adrienne tried to get Sonny to change his mind about Will, but he told her that while he loved her, he was a grown man and could make his own decisions. Justin also warned Adrienne to stay out of Sonny's life. But, she was determined.
When Adrienne discovered the video on her phone, she first went to see Sonny. But, because she had worn Sonny out with her nagging before, he stopped the conversation before they got in an argument. Then Adrienne went to see Justin. But, when Adrienne saw that Justin was considering a job offer from E.J. they got into a huge fight and Justin left rather than continue to argue with Adrienne.
Feeling as though she was protecting Sonny, Adrienne took the video to the D.A. in exchange for immunity from any potential charges for herself and Sonny. The D.A. was thrilled and charged Sami with first degree murder. Justin was furious with Adrienne for going behind his back and not only meddling in Sonny's life, but in Justin's professional life as well. Justin moved out of the mansion and into the club for a while.
But Adrienne wasn't the only one Justin was angry at. Justin was ready to dropped Sami as a client since she had E.J. had lied to him. But, Will told Justin the truth -- how Sami was lying to protect him. Justin understood and kept Sami on as a client. He also asked Will and Sonny for $1 each so that their conversations would be protected by attorney client privilege. Justin proceeded on with Sami's defense.