Rey Rosales was brought in to Genoa City 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 was obsessively insecure about her relationship with Rey, and yet continually coming on to Arturo. 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. Mia 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 deserve Arturo. Later Mia thought she had found Abby at Abbott Manor, but it was Lola in Abby's hooded coat there to see 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, Lola's brother 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. He agreed to keep Mia's secret. But viewers had seen Mia propositioning a pregnant woman prior to the test.

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 the 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 recently, 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. Sharon was shocked to find the photo of a fetus that Mia had left on her door marked as their baby's first photo. She and Rey discussed it, and Sharon understood, but told Mia to back off or else, saying she knew she was the one who had injured Lola.

Mia met with Phyllis Summers and agreed to join her accessories company after Phyllis flattered her as a woman who wanted to look fashionable without breaking the bank.

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. Ray and Arturo hugged, and Arturo and Mia left together for Miami. Ray filed for divorce, saying they deserved each other. 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. Mia and Arturo were later married.

In April 2022, the family was crushed to receive word from Sharon that Rey had a heart attack, causing a car accident, and had died. Celeste insisted that Rey's body be sent to Miami and he be buried there. Sharon had a family memorial in Genoa City then attended the funeral for Rey in Miami (which was not seen onscreen).