Little is known about Damian Spinelli prior to his life as a college student at Port Charles University. His grandmother raised him in Oakfield, Tennessee.

Damian Spinelli was a student at PCU when Lorenzo Alcazar hired him for his expert computer skills. Lorenzo paid him to create a flash drive with false incriminating evidence against Sonny and Jason. Later, Ric Lansing used the "missing" flash drive to frame Sam McCall in the hopes of forcing Jason to make a mistake. Jason didn't. Instead, Jason started following the clues and eventually figured out that Spinelli was the key to exposing Ric's corruption and his association with Lorenzo. However, the false evidence implicated Sam.

Spinelli was completely unprepared for the situation he found himself in. A self-professed computer geek, Spinelli's strength was his mind, not his brawn.

Jason and his girlfriend, Sam, took Spinelli to a safe house but, during an attack by Lorenzo's hit-men, he disappeared. He reappeared and met Lulu Spencer. Lorenzo had kidnapped both, but Spinelli escaped once again. Lulu and Jason tracked him down to his grandmother's home in Tennessee.

Eventually, Spinelli was able to debunk the information on the flash drive, which exonerated Sam. Because Jason rescued Spinelli several times from Lorenzo's henchmen, Spinelli's vowed his eternal gratitude and undying loyalty.

Initially, Jason tolerated the strange young man. He comprehended very little of what Spinelli said because Spinelli had a unique way of saying things, but eventually they grew to be close friends. It was Spinelli who became one of Jason's few confidants when Jason learned that the baby that Elizabeth Webber carried was Jason's. Spinelli urged Jason to step forward, convinced that Jason would be a wonderful father. Jason was reluctant because his career choice as a mob enforcer endangered his son. Spinelli disagreed, but he supported his friend's decision. As time passed, Jason took Spinelli under his wing. He gave Spinelli a job as his computer expert and invited Spinelli to move into the penthouse.

Spinelli partnered with Dillon Quartermaine and Lulu to find out who had killed Lulu's grandfather, Rick Webber, years before. Previously, everyone had believed it had been Lulu's mother, Laura, but just before she went back into a catatonic state, she asked Lulu to prove it was Scott Baldwin who had killed Rick. After Alan Quartermaine died, Spinelli, Lulu, and Dillon found a letter from Alan that was addressed to Luke. In it, Alan admitted that Scotty had accidentally killed Rick when he thought Rick had murdered his ex-mistress and was trying to drug Laura. However, it was Laura who had accidentally killed the woman.

Spinelli supplied marijuana to a very sick Alexis Davis as she battled lung cancer. Due to her treatment, Alexis became very nauseous and weak. Spinelli convinced her that marijuana was a very safe and effective way to ease her symptoms.

During the hostage crisis at the Metro Court Hotel in February 2007, Spinelli worked with Jason to rescue the hostages from Jerry Jacks. It was revealed that Spinelli had a crush on Lulu.

Jason discovered that Georgie Jones had a crush on Spinelli and told him. Spinelli was overjoyed, but confused. Tragically, he discovered her dead body in the park on December 17, 2007. She was a victim of the Text Message Killer. Spinelli felt guilty because he had been unable to protect Georgie. The Port Charles Police Department named Spinelli a suspect in the murder. After Maxie Jones's boyfriend Cooper Barrett's apparent suicide, Georgie's sister Maxie grew to believe that he'd actually been murdered. She enlisted Spinelli in the hunt for Cooper's killer, assuming that it was the Text Message Killer. Spinelli and Maxie did not get along at all, arguing at every turn.

While searching for clues, Spinelli and Maxie became trapped in a storm drain and had to spend the night. It was during this escapade that Maxie began to soften in her attitude toward him. Lulu began to suspect Logan Hayes was the serial killer. During a stakeout at Logan's apartment, Maxie kissed Spinelli to avoid the suspicion of a cop. It was at that point that Spinelli began to fall for her.

Eventually, it was discovered that Diego Alcazar, presumed dead, was the killer. During a confrontation between him, Spinelli, and Maxie, Diego fell to his death.

After Sonny kidnapped Claudia Zacchara's brother, Johnny, Claudia sought revenge. She worked with Jerry Jacks and arranged for Ian Devlin to assassinate Sonny in his coffee warehouse. Unfortunately, Sonny was giving his young son Michael a tour of the facility that day. Devlin missed Sonny, and the bullet ricocheted, hitting Michael in the head. Michael spent the next year of his life in a coma.

Maxie and Spinelli worked together once again to find the assassin. They discovered that Ian Devlin was the culprit. In another fateful confrontation, Jason saved Spinelli and Maxie by shooting Devlin to death.

Spinelli admitted to Jason that he'd fallen in love with Maxie. He also sought relationship advice from Diane Miller, Sam, and Jasper "Jax" Jacks. At that point, Spinelli began to woo Maxie.

With Johnny's aid, Spinelli helped cover up the accidental death of Logan at Lulu's hands. Soon thereafter, Johnny's deranged father, Anthony, kidnapped Maxie. She escaped and made her way to Spinelli. He promised to keep her safe. Out of appreciation, she made love to him but immediately regretted it, believing she used him for comfort sex.

During a stakeout, Maxie was nearly hit by a car before Spinelli pushed her out of the way and was struck by the vehicle. Maxie rushed him to the hospital where Matt Drake operated on him to remove his ruptured spleen. After surgery, Spinelli developed an infection. Matt's brother, Patrick, successfully worked to save Spinelli. While Spinelli recovered at Jason's penthouse, Maxie cared for him.

Kate Howard, Maxie's boss, hired Johnny to accompany Maxie to highly publicized events that could be showcased in Crimson, Kate's magazine. The two flirted and went so far as to make out when stuck in traffic once, but they never went any further.

Spinelli discovered that his computer had been hacked shortly before meeting a girl named Winifred Leeds, who was having computer troubles herself. When she realized who Spinelli was, Winifred melted. She was a huge fan of the online game he'd created, "Stone Cold Saga." Her computer prowess matched that of her idol, and the two became fast friends. Maxie was jealous and possessive; she told Spinelli that Winifred was not to be trusted.

It became obvious that Winifred was falling for Spinelli, but he made it clear that his one love was Maxie. It was soon revealed that Winifred was an FBI agent, working to take down the Corinthos empire, and was using Spinelli to surreptitiously gather evidence against Sonny and Jason, as well as Spinelli. However, she began to develop true feelings for Spinelli.

Feeling threatened, Maxie seduced Spinelli. When he realized that the sex had been merely an attempt to distract him from Winifred's charms, the two argued. Before Maxie had a chance to apologize, he was arrested for violations of the Homeland Security Act.

Early in 2009, an accident victim arrived at General Hospital. During surgery, it was discovered that he'd been transporting spheres in his stomach. One of the spheres was punctured during the operation, releasing a deadly biotoxin. The surgical team was rendered unconscious. Out on bail, Spinelli found himself at the hospital when the poisonous gas made its way into the ventilation system.

A Hazmat team rescued the surgical team from the OR, but not before one nurse died. However, the oxygen had been left on, which led to an eruption of flames. The fire quickly became a conflagration, trapping many Port Charles residents. Spinelli kept in contact with Winifred, who had left the building, using his laptop computer.

After the hospital's wireless connection went down, Spinelli looked for a way to use the facility's communication system, but became trapped in a utility closet. An explosion knocked him out, but Jason and Sam rescued him. Upon reaching safety outdoors, Spinelli and Maxie were reunited and kissed passionately.

The following day, Winifred's superior, Agent Rayner, threatened to arrest Spinelli unless he was provided with enough evidence against Sonny to put Sonny in prison. Winifred urged Spinelli to go on the run and, later, showed up on his flight to Los Angeles, surprising him.

While Spinelli was in L.A., Cassandra Prescott kidnapped him and ordered him to help her break into a gallery to steal a ten-million dollar painting. He got a coded message to Winifred, but it was Maxie who was able to decrypt it. The two women, with the aid of Jason and Sam, rescued Spinelli. Winifred took full credit for capturing Prescott, so that the rest would not be implicated.

Because of her exemplary work preventing the heist, Winifred was promoted. This allowed her access to the files that incriminated Spinelli. With her help, Spinelli was able to release a worm onto the FBI computer system, which destroyed all evidence against him. He and Sam worked together to destroy the physical evidence, enabling Spinelli to eliminate the threat of prison. Soon thereafter, Sam and Spinelli partnered to become Jackal and McCall Private Investigations.

Maxie's stepfather, Mac Scorpio, did not like Spinelli, mainly because of his involvement with the mob. He forbade Maxie from seeing Spinelli, so she moved into Lulu's apartment. In July of 2009, Spinelli arranged to alter his voice electronically to sing a love song to Maxie at Jake's on karaoke night. However, the device was damaged before he went on stage, but he sung from his heart, which won hers. They made love that night. The following morning, he proposed to a stunned Maxie. She refused to give an answer at first but later admitted that she wasn't ready for marriage. Spinelli courted Maxie the old-fashioned way, and the two, to Maxie's dismay, remained chaste.

Spinelli decided to again ask for Maxie's hand in marriage and planned an elaborate date. He left her clues that he thought would lead her to the rooftop of the Harbor View Towers. But the clues were misconstrued, leading Maxie to Wyndemere, the Cassadine castle on Spoon Island. She eventually made her way to a distraught Spinelli, and the two shared a romantic evening together. Again he proposed, and again Maxie declined.

Spinelli decided to try to win Maxie's hand in marriage one more time -- this time, at a family dinner with Mac, Maxie, Robin, Patrick, and Lulu. Mac became enraged and hurled epithets at Spinelli. Maxie, to defy her stepfather, agreed to marry Spinelli.

As their nuptials approached, Maxie worked to convince family and friends that she really wanted to marry Spinelli but admitted to Lulu that she'd made a mistake. Lulu urged her to call it off, but Maxie refused to break Spinelli's heart. Just before the rehearsal, Maxie told Jason that she feared she'd leave Spinelli at the altar and begged him to make sure she went through with the wedding. Spinelli overheard this.

During the ceremony, when it came time for him to recite his vows, Spinelli released Maxie from her obligation, stating that they should be wed only if it was what they both wanted. They both expressed their mutual gratitude and love and vowed to be the best non-husband and non-wife they could be to each other. Mac was very relieved. Friends and family celebrated the non-wedding at Jake's.

Kate Howard, Maxie's boss, arranged for Maxie to welcome well-known artist Franco before his art show. She agreed to pose for him. He blindfolded her and posed her lying on the ground inside of a chalk outline. When she realized what he'd done, she exploded, explaining that her sister had been murdered. He apologized. Soon, Franco's intensity lured Maxie, and the two slept together.

Spinelli sensed that Maxie might be feeling trapped in their relationship and arranged for the two of them to recreate the moment at which they had both begun to fall for each other -- the night they were stuck together in a storm drain. Again, they became trapped, for real, and spent the night until Johnny rescued them. During the event, they both developed hypothermia and ended up in the hospital.

Maxie developed pneumonia and, as a recipient of a heart transplant during childhood, she nearly died. Spinelli begged an unconscious Maxie to return to him. Between life and death, Maxie was reunited with Georgie, who said that Maxie had too much to live for and suggested she go back to her true love. Spinelli realized that he was constantly putting Maxie at risk. He considered breaking up with her, for her own safety, but she refused.

After Michael was convicted for manslaughter in the death of Claudia, his mother, Carly Jacks, hatched a plan to destroy the lives of everyone she thought was responsible, including Michael's half-brother, Dante Falconeri, and Dante's girlfriend, Lulu Spencer. Carly enlisted Spinelli's help. Spinelli, distraught that Jason had confessed to crimes in order to be sent to prison to protect Michael, agreed to help her, and began digging up dirt on everyone Carly targeted.

Jason realized that Carly had drawn Spinelli into her revenge scheme and warned him against it. However, Carly remained focused on taking Lulu and Dante down and successfully thwarted Lulu's attempt to make peace with Spinelli. Taking advantage of Spinelli's computer expertise, Carly asked him to transfer seemingly illegal funds into Dante's bank account to make it look like he was a dirty cop.

When Jason was released from Pentonville, Spinelli focused his efforts on helping his mentor and boss track down the elusive serial killer, Franco. An infamous mob kingpin, known as the Balkan, was targeting Sonny's past love, Brenda Barrett. In an effort to find the Balkan, Jason instructed Spinelli to uncover everything about Brenda from the time she left Port Charles. It was a difficult task because the Balkan had taken great pains to be invisible, even in cyberspace.

When Brenda arrived in Port Charles, Spinelli was smitten and dubbed her "The Divine One." He went out of his way to buy Brenda's favorite organic foods and to make sure she wasn't disturbed when she did her yoga and meditation. That did not sit well with Spinelli's past love, Maxie Jones. Brenda sympathized with Spinelli over his love life and confided in him that she always hurt the men she loved. She then used her charms to dupe Spinelli into revealing the location of a Balkan trade that she thought she should be in on.

Carly and Brenda's enmity for each other could be traced back to their tangled love lives with both Sonny and Jax. Although Carly had since married Jax, Carly was upset that her ex-husband, Sonny, planned to marry Brenda. Once again, Carly enlisted Spinelli's help in digging up dirt on her rival. Spinelli was reluctant because he adored Brenda.

When Spinelli uncovered a lead about Brenda's past that he knew would devastate her, Carly pressed him to dig deeper. The lead had to do with a family lawyer and a baby. Spinelli was distraught and did his best to hide Brenda's secret. Eventually, Spinelli spilled the beans to Jason that Carly had the means to stop Sonny and Brenda's wedding. Spinelli begged Carly not to reveal the evidence that proved Brenda and Dante shared a child.

Despite Carly's best efforts, Brenda and Sonny managed to get married. Right after the reception, the Balkan staged an explosion and kidnapped Brenda. It was Spinelli who discovered that the Balkan was hiding in plain sight, masquerading as Theo Hoffman, a lawyer in Diane Miller's firm. Spinelli's cyber sleuthing also led to the discovery that Brenda's confidant and friend, Suzanne, was the Balkan's wife. That discovery proved to be crucial in taking down the Balkan.

Spinelli overheard Diane Miller working on a novel and was impressed by her literary talent. They decided to write a book together, using cases from Spinelli's P.I. files. They titled it The Secret Life of Damian Spinelli. Spinelli told a very pleased Maxie that she was the inspiration for his book. Spinelli had many fantasies about being a gumshoe that ended up in print.

Jason was less than pleased when he discovered he was a character in the book. Because Diane was Jason's lawyer and had saved him from doing jail time on numerous occasions, Jason agreed to sign a release. After the book was published, Diane proposed doing a sequel. One day while she waited for Spinelli in his office, Diane started to search his secret case files for story ideas. Spinelli was furious and ordered her to stop. Diane was miffed that Spinelli denied his co-author access. Spinelli told her the files were sealed for a reason, leaving Diane to ponder the meaning of his secretiveness.

Spinelli stood by his friend and mentor after Jason's son Jake died after being hit by a car. Sam and Jason decided to move ahead with their plan to have a child and Spinelli was supportive of the idea. Spinelli rushed Sam to the hospital when she experienced stomach cramping on a stakeout. As Spinelli eagerly awaited Sam's pregnancy test results Lisa Niles took Robin, Patrick, Steve Webber, and Maxie hostage in a hospital conference room.

Spinelli was distraught when he learned Maxie was in danger. He leaped into action and climbed through a vent that ended in the conference room. He crashed through the ceiling and tried to secure Maxie's safe release. Lisa shot at Maxie but hit Spinelli instead when he jumped in front of the bullet meant for Maxie.

Spinelli's gunshot to the chest required emergency surgery and Maxie's boyfriend Matt Hunter performed the operation. While Spinelli was unconscious, he imagined he was a gumshoe from decades past and when he awoke he had a new persona. He spoke as if he were an old-fashioned gumshoe and referred to Maxie as a "dame' and called Diane "cookie." Spinelli referred to himself as "Jackal P.I." He recognized everyone and his memories were intact but he no longer possessed his super computer skills.

As Jackal P.I., Spinelli enraged Sonny when he took twenty million dollars from him and warned him he was cracking down on organized crime in the city. Maxie intervened and protected him from Sonny's wrath. Jackal P.I. went after Anthony Zacchara next and confronted him with a gun. Maxie informed Jason of Jackal's plans for Anthony and Jason hired Jackal to watch a bakery for evidence it was a front for drug smuggling. Jackal was unaware that Jason had made up the job to keep him out of trouble.

Maxie continued to feel responsible for Spinelli's Jackal P.I. persona and she continually tried to jog his memory. Her first strategy was to remind him of their past together which included a kiss and a trip to a sewer. Jackal P.I. did not respond to Maxie's advances and she was annoyed when he developed a crush on Lulu and gave her the nickname "Moonlight."

The persona of Jackal P.I. started to lose hold over Spinelli when Maxie took him to Georgie's grave. He initially claimed he did not know her but Maxie could tell she was getting through to him when he warned Maxie not to become too emotional due to her heart condition. He told Maxie she needed to stay away because he could not care about anyone because he would only lose them. Maxie agreed to give him space. Jackal P.I. immersed himself in his stakeout of the bakery and he discovered there was something mysterious going on.

Maxie made another attempt to bring back Spinelli while Jason was hospitalized after he experienced head trauma from a car accident Maxie claimed Jason asked Spinelli to be his best man when he married Sam and convinced him to visit Jason. As Jackal P.I. struggled to remain composed in the presence of his friend, Spinelli broke through and begged his mentor to survive.

Spinelli was relieved when Jason was released from the hospital and was able to marry Sam. While the newlyweds were gone on their honeymoon, Spinelli revealed to Maxie that his cyber skills had disappeared but he found a way to access information using a network called Friends of Spinelli, or FOS. He contacted his network whenever he needed information he could retrieve on his own. He used FOS when Franco left graffiti tags around Port Charles shortly after Sam and Jason returned from their honeymoon. His connections deciphered the tags as having a message related to creation and they also found Franco's location so Jason could kill him.

As Sam and Jason settled into married life the time came for Spinelli to find a new place to live. He had decided to pursue Maxie again despite her relationship with Matt and he moved in as her roommate. Maxie remained committed to Matt even though she questioned Matt's interest in Elizabeth Webber. Maxie asked Spinelli to help her make Matt jealous by spending time with her and he agreed.

Spinelli hoped to win Maxie's heart once again but his pursuit of her was sidetracked when Jason was hospitalized after he suffered another health crisis. Jason and Sam told Spinelli that they were expecting a child and that posthumously Franco had sent them video footage of Jason as an infant. Jason asked Spinelli to look into the authenticity of the footage.

Eventually Jason made a full recovery but his recovery was bittersweet as Doctor Robin Scorpio-Drake died in a lab explosion after creating the drug protocol that saved Jason's life. Spinelli broke the news to Maxie that her beloved cousin had died and he promised to remain by her side while she grieved. Spinelli had concerns about how Maxie handled the loss especially after she claimed she would not attend Robin's funeral. She did eventually attend and announced that she had killed Robin.

Spinelli believed that Maxie was in shock due to her grief and he and Maxie's friends and family explained that although her purse strap caught on a gas line, Robin's death was an accident and not her fault. Maxie refused to accept that reasoning and was angered when her father refused to arrest her for killing Robin. She then confessed to the murder of Lisa Niles and Mac was forced to take her into police custody.

Maxie also confessed to the murder of Officer Briggs and claimed she had framed her to take the fall for Lisa's death. Maxie was officially charged with the crimes after the man Maxie supposedly hired to forge Officer Brigg's suicide note identified her as the person that had hired him to write the note. Spinelli maintained Maxie's innocence and he begged her to recant her confession.

When Maxie remained determined to be punished for Robin's death in any manner possible, Spinelli teamed up with Matt to find the real killer. They reenacted the night of Lisa's death and Spinelli investigated each person that may have killed Lisa but to no avail. Maxie plead guilty and the date of her sentencing hearing arrived shortly after. Just before the hearing, Spinelli realized that Matt had been so intoxicated the night of Lisa's death that he could have killed Lisa and not remembered what he had done.

Spinelli brought his idea to Maxie and she confirmed that Matt had in fact killed Lisa but did not remember doing so. She begged Spinelli to let her take the fall for Matt so he could be there for Patrick and Emma in Robin's absence. She explained that she had already taken Robin from them and she refused to take Matt away from them as well. Spinelli agreed although it pained him to see Maxie sentenced to twenty years in prison without parole. As Maxie was taken away he vowed to clear her name.