Rey was the oldest child of a Cuban family born and raised in Milwaukee, Wisconsin. When their father abandoned them when their mother was pregnant, Rey took over raising his younger siblings Arturo, and Lola after she was born. Rey likes to say he spent his life cleaning up Arturo’s messes, who got in a lot of trouble. Always at odds, Arturo says he borrowed a neighbor kid’s bike to get a prescription for their mother, Rey says he stole it.

Rey was brought in from Miami and the U.S. Department of Justice by DA Christine Williams to take over the J.T. Hellstrom case. J.T. was the prime suspect in two attempts to murder Victor Newman, but had suddenly disappeared. Rey was long separated from his wife Mia, and became close friends with Sharon Newman, his deskmate, who was the GCPD victim liaison.

Rey’s brother Arturo had arrived in town five months earlier, had secured an important job as head of construction at Dark Horse, and was involved with heiress Abby Newman. Arturo was not happy to see Rey again after all the years. Lola, who had arrived a month earlier, and was a great cook, owned a food truck named “La Vida Lola” featuring Cuban Authentic Street Food. Lola tried to get the brothers together to forgive and forget. Lola was dating Kyle Abbott whose grandfather was the founder of Jabot Cosmetics. No one was happy to see Rey’s brassy estranged wife Mia show up in town intent on repairing their marriage. But Rey let her move in, and tried. She got drunk and caused a scene at the Jabotique launch party, exposing that she had an affair with Arturo which is what had broken up her marriage to Rey. Mia insisted they have a vow renewal ceremony. Arturo got caught up in the moment and proposed to Abby, who accepted.

After Victor Newman’s stables burned to the ground and a shirt with J.T.’s blood on it and a gun were found in the remains, Rey arrested Victor for J.T.’s murder and he was jailed without bail. His wife Nikki confessed that she had killed J.T. in defense of her daughter.

Rey and Sharon were caught in a snowstorm, hit ice and spun out, while on police business. With the car needing repair they stopped at motel in Kenosha, which only had one room left with a full-size bed. They were careful to keep their distance, so nothing happened, but they were obviously tempted. Meanwhile, Arturo was helping Mia fix the heat in Rey’s apartment, but he didn’t have the parts. She came onto him, and they ended up cuddled on the couch to keep warm and had sex.

Mia had a drunken argument with Arturo’s girlfriend Abby Newman, telling her she didn’t belong with Arturo. Later Mia thought she had found Abby at Abbott Manor, but it was Lola in Abby’s hooded coat there to see her boyfriend Kyle. Mia smashed Lola’s phone and knocked her down from behind, causing Lola to hit her head, and fall into the pool in freezing weather. Kyle found Lola, pulled her out, and called 911. Later in ICU, Arturo knowing they had broken up, made Kyle leave. Rey vowed to make the attacker pay. Mia was there clinging to Rey, shocked to find out that she had attacked Lola instead of Abby. Lola was in a coma. They also discovered that her liver was failing, and she needed a donor.

Rey and Mia made love, but Mia moaned Arturo’s name. Rey got out of the bed and left mad. Rey was not allowed to work the case to find Lola’s attacker, but managed to see the evidence which included an earring he recognized as belonging to Mia. Rey confronted Mia and was about to arrest her, when Mia claimed she was pregnant. Rey insisted on a test which came out positive. So he agreed to keep Mia’s secret.

Days later Rey told Sharon that he loved her. Then Rey found a phone bill saying Sharon had called 911 the night that J.T. had disappeared. Rey got Sharon to confess the true story of how Nikki had killed J.T. as he attacked Victoria, and how Sharon and Phyllis had helped them bury his body in Chancellor park.

Nikki was charged with second degree intentional homicide and obstruction of justice, and Sharon and Victoria for being a party to both. Phyllis turned states evidence and became the star witness for the prosecution. Sharon had her own attorney in Brittany Hodges, whose case was that Rey had illegally coerced Sharon into confessing her part, and had read her no Miranda rights. The rest were represented by Michael Baldwin. Brittany called Rey as a witness, and in front of Mia, he admitted telling Sharon he loved her, and that she had said she loved him too. Rey claimed it had not been a trick, that he was happily married. Mia stormed home, and told Rey she couldn’t forgive him. Rey said good, that he loved Sharon.

Rey, Arturo, Mia, and Kyle were tested but not a match for Lola. It was Kyle who brought Lola out of her coma. Dr. Nate delivered the news that they had found a donor who wished to remain anonymous. Both Lola and the donor came through fine. Kyle broke Lola’s heart by admitting that he had married Summer to convince her to donate part of her liver to save Lola.

All three Newman women were found guilty and sentenced to prison. On their way to prison, Rey arranged for the women to escape and hide out at the Abbott cabin to trap J.T. after Nick had finally convinced Rey that J.T. was still alive. But J.T. knocked out the guards and held the three women inside with hands and feet zip-tied. J.T. ranted at them for trying to kill him and bury him alive, and began smashing things. He explained that he had been buried over a storm drain, his body had fallen in and sent out to the river. Writhing in pain, J.T. ruptured the fireplace gas line by wielding a poker. He passed out from the pain, and the women from the gas. Billy Abbott, Nick and Victor Newman rescued them. Rey arrived and told everyone that they had to tell the truth about what had gone on. DA Christine was livid with Rey. She upheld only the women’s obstruction charges, but revoked their sentences. Paul reprimanded Rey and fired him. The police officers who had helped him were charged. Sharon was given another chance at her job, but she fought for Rey and quit when Paul refused to reconsider his firing.

Rey came home to find Mia packing, she got madder when she heard all that he had given up for his precious Sharon. Mia spitefully told him that she had slept with Arturo again, so Rey kicked her out. Rey brought Lola home from the hospital to stay with him rather than go back to live with Arturo.

The next day, Rey met Sharon for dinner, and they ended up at her place and made love. He spent the next couple days there until Nick interrupted them to offer Sharon a job at Dark Horse. Sharon turned down the offer. Then Sharon was shocked to find the photo of a fetus that Mia had left on her door marked as the first photo of Mia and Rey’s baby. Sharon and Rey discussed it, and Sharon understood, but warned Mia to back off or else, saying that she knew Mia was the one who had injured Lola.

Paul asked Rey to do some investigating and find out what Victor was up to for Nikki, so Rey and Sharon went to Vegas together. There they found Victor was involved with a gambler named “Spider”. When they got too close to the truth, Victor intervened and let them know that “Spider” was his son Adam, who had not been killed in an explosion after all. Victor asked Sharon, who was once involved with Adam, to meet “Spider” and try to help him regain his memory which the explosion had caused. Sharon was unable to spark a memory, but convinced Adam to return to Genoa City with them. Sharon was totally up front with Rey about her relationship with Adam. Sharon confessed that during her life with Adam, she had burned down Victor’s house, been diagnosed as bi-polar, and Adam had saved her and gotten her help. And how Adam had saved Faith’s life during a tornado. Both Rey and “Spider” did a lot of research on the Internet and were convinced that Adam was not a good man, not someone that Adam wanted to become, or Sharon would still want to be involved with. They all returned to Genoa City, and Victor put Adam up in the tack house on the ranch.

Arturo let it slip and Lola guessed that Mia had been the one who attacked her, thinking it was Abby. Lola confronted Mia, Abby overheard and joined in. Abby was about to call the police, but Lola talked her out of it for Mia’s baby’s sake. But later Paul questioned Mia and she told him what had happened that night, then cried out in pain. Mia was taken to the hospital, but was fine later. Rey accused her of faking it for Paul. Neither Abby or Lola would file charges against Mia. The pregnancy was far enough along that a blood test was taken for paternity which revealed Arturo was the father. Rey and Arturo hugged, and Arturo and Mia left together for Miami. Rey filed for divorce, saying they deserved each other.

Rey finally met Sharon’s daughter Faith. After spending some time together, Faith asked when he was moving in. Rey was taken aback until Faith said it was okay, that she approved. Rey and Sharon discussed it, and decided it was a good idea, promising no secrets between them ever again. Rey moved in, and informed Lola and Kyle they could stop looking for a place together and take his apartment, which they did.

Nick Newman surprised Rey by offering him a job as head of security at Dark Horse, mentioning that it included some personal security for his son Christian whose father Adam had returned and wanted him back. Rey accepted the job after discussing it with Sharon. Adam continually came to Sharon for support, coming between Rey and Sharon. Rey told Sharon he couldn’t deal with the fact that she hadn’t gotten over Adam, so their relationship was over, and he moved to the athletic club. Rey also quit working for Nick keeping track of Adam, and begged Paul for his GCPD job back. Paul finally relented, warning Rey this was his last chance.

Lola’s mother Celeste was a surprise guest flying in from Miami for Lola’s bridal shower. The next day a get-together was thrown to meet the Abbott family. Celeste flirted with Jack and insisted on a tour of Abbott Manor. Celeste announced that she was staying in town until after the wedding, and she attempted to take over the planning from Kyle. Rey took Lola aside and let her know that Celeste was seeing their father again and lending him money. Rey told Lola the truth, that Adrian had not abandoned them, Celest had kicked him out after he cheated on her. Theo, Kyle’s former New York City cohort who was jealous of Kyle’s new life, worried Celeste about Kyle’s character. He informed her how Kyle had coerced Summer to donate part of her liver to save Lola’s life. Celeste confronted Lola and Rey that she had not even been told when Lola was in a coma. Celeste left upset for Miami, and said she would not be back for the wedding.

Guests arrived at the romantically decorated venue, and Lola was in awe. Her wedding gown was beautiful and she and Kyle glowed. Celeste showed up, and Lola invited her to walk her down aisle with Rey. Celeste spotted Lola’s father Adrian watching from behind the hanging silk. She cornered him, but could not get him to leave. Later Lola was not happy to see Adrian, who tried to apologize to her. She said she wouldn’t let her ruin her big day, and told him he could stay or leave, she didn’t care. A few days later, Celeste convinced the brothers to reconcile, and they hugged goodbye with Rey asking for photos the minute Arturo and Mia’s baby was born. Arturo sent the photos to Rey and Lola with news that they had named their baby boy Mateo.

Sharon was getting too involved with Adam Newman and being manipulated by him. Rey finally said enough, called off their relationship and moved out. It wasn’t a day later that Sharon and Adam were making love in his repurchased penthouse. But Sharon realized it would never be a healthy relationship, and ended it. Some months later, Sharon and Rey reunited.

Not long after Christmas 2019, Sharon discovered a lump in her breast. Not wanting to alarm anyone she had a needle biopsy and a malignant tumor was discovered. She confided her fears in Rey who was very supportive. Dr. Blakely, a specialist, confirmed it was stage 2 cancer, suggested chemotherapy, then surgery. The chemo gave Sharon chills and nausea, and when her white blood cell count became too low, she had to stop chemo. Before scheduling a lumpectomy, she had a biopsy on her lymph nodes to see if it had spread, but it had now. Rey was totally supportive, Faith transferred back from boarding school to Walnut Grove to be near her, and Mariah skipped going on tour with Tessa. Sharon had the lumpectomy and was still expecting more chemo and radiation treatments. But Sharon's cancer spread to her sentinel lymph nodes requiring a second surgery, then chemo. In the middle of all this, Adam wanted Sharon to rescue him again, she said no and proposed to Rey. Eventually Sharon's margins were all clear.

Rey and Sharon were married on New Year's Eve at Society. Nick was best man, Mariah maid of honor, Tessa wrote their song for the ceremony, but had to give them a CD to make a New Year's Eve gig in New York City. Arturo officiated, mentioning that he loves Mia, and the 3 of them were very happy. Celeste spoke to Sharon virtually because she had to work. Adam watched from the hallway. Phyllis caught him, but he said he was not there to disrupt, just glad to see her happy. The couple honeymooned in Miami. Rey gave Sharon an ultimatum no more Adam.

Rey started feeling horrible and ended up in the hospital. It was discovered that he was being slowly poisoned. The house was checked, and the poison was found in his toiletries, so it was determined that someone was attempting to kill him. Adam was the prime suspect. But it turned out that Chelsea, who had a stroke and was incapacitated, had recovered and was faking. She had gotten Chloe to plant the poison and was trying to frame Adam for attempted murder because she was convinced he was having an affair with Sharon. Rey was the one who confronted Chelsea and arrested her. After she was found innocent by reason of insanity, Chelsea asked for Rey to forgive her. He did, and they became close friends. Rey became a father-figure to Chelsea's son Connor.

One foggy night Rey had agreed to take Connor to a professional hockey game in Chicago. When they met at Crimson Lights, Rey realized he had left the tickets in his other jacket. Rey drove home to get them, but on the way back he had a heart attack that made him veer into oncoming traffic. Victoria steered to avoid him and hit at tree. Rey crashed into Ashland who had been following Victoria causing Rey's car to flip. Victoria was unconscious in her car, Ashland trapped in his by a tree branch. As Victoria's car started on fire, Ashland found the strength to break out of his and rescue Victoria, saving her life. Nick had to break the news to Sharon. Everyone in Genoa City loved Rey and was devastated by his death. Sharon contacted Rey's mother Celeste who insisted the funeral and burial be held in Miami. After discussing it with her family Sharon realized that it was the right thing for a mother to want her son buried near his family home. A memorial service was held in Genoa City, then Sharon attended the funeral in Miami. (Both happened off screen.)

Tessa's sister Crystal was able to attend Tessa's wedding because Rey had intervened and gotten all the charges against her dropped, and Zach arrested. Mariah saw it as one last gift before he died. Trying to make amends to the Newman family, Ashland donated 250 billion dollars to New Hope in the name of Rey Rosales