Hunter was born on the 10th May 1965 in Glasgow, Scotland into a criminally active family. He had an older sister, Samantha Hunter, who was one year his senior. His family later moved to the unnamed city where the show takes place in the 1970s.
He followed family tradition and became involved in organised crime from a young age, in diametric opposition to his older sister, who hated what the family stood for. In 1979 when he was 14 he raped Samantha, and she was forced to relocate back to Glasgow and carry the pregnancy to term, eventually giving birth to Joanne Davidson. In 1982 Hunter had a son, Darren Hunter, with an unnamed woman.
Becoming the senior kingpin within the Organised Crime Group, he employed a teenage Matthew Cottan to work for him as a golf caddy at the Edge Park Golf Club. He subsequently induced Cottan into the world of crime, and encouraged him to join Central Police in order to act as his man on the inside. He would also do the same with his niece/daughter Joanne Davidson in 1996.
Hunter is mentioned by name for the first time when Ryan Pilkington delivers a burner phone to Wesley Duke on the Borogrove Estate. He accuses Duke of dealing with rival Arab drug dealers (who were killed on Greek Lane), and says that unless he provides Ryan with his entire score, he will meet a similar fate.
Hunter is later mentioned when DCI Tony Gates is kidnapped by his men and taken to the location of Jackie Laverty's body. He speaks with Gates on the phone, claiming he works for him now, unless he wants the police to find her body with his "dirty business" all over her.
Hunter contacts Gates again via mobile phone regarding the status of the money laundering case. Infuriated that Gates has been unable to disband the investigation completely, he accepts the fact it has been passed on to the Fraud Squad and will likely not be touched by the CPS due to its complexity and the absence of any key suspect.
Hunter later contacts Gates again regarding DS Steve Arnott's enquiries into the hairdressing salon used by him and Jackie Laverty to launder money, claiming he needs to shut it down. Blaming Gates for this, he demands that he lure Arnott to a specific location so he can "be fixed" and will no longer cause interference. After Arnott has been captured by his men, Hunter speaks with him on the phone, demanding to know what he knows about his activities. As Arnott is tortured, Gates pleads with Hunter to give him Jackies body and release him, but Hunter smirks "What, and ruin our relationship?" before hanging up the phone.
With the help of AC-12, DCI Anthony Gates is able to track Hunter's whereabouts to the Edge Park Golf Club via mobile cell triangulation. However, before DS Steve Arnott and DC Kate Fleming are able to catch up to him, he takes Hunter into custody and drives away.
Gates questions him in the car, with a microphone and recording being patched into Arnott and Fleming's vehicle. Despite Gates' leading questions, Hunter does not say anything that could implicate him, and claims that there is no evidence against him. Gates then claims that he could still be of use to Tommy, claiming that he dressed up the Greek Lane murders as a Counter Terrorism case, and is planning on making the murder of Wesley Duke look like a simple rivalry killing. He states that since one of Hunter's men got sloppy by cutting off Duke's fingers, and the lack of forensic evidence means he will need a confession. Hunter agrees to have one of his men confess to the killing, in order for the attention to be drawn away from himself. Gates claims he needs better assurances from Hunter if he is going to be able to help him, which prompts Hunter to lose his temper and yell "For f*ck's sake! He killed him! On my orders!" much to the delight of Arnott and Fleming.
When Gates then demands that Jackie Laverty's body is returned to him, Hunter refuses, claiming it is his only leverage. He then goes back to threatening Gates, claiming that if he steps out of line again her body will be brought out and he will go down for her murder. However, he is then arrested by Gates, who promptly commits suicide afterwards. Once he is arrested, he is questioned on scene by DS Matthew Cottan, who is now leading the investigation into the Greek Lane murders. The two are revealed to be in cahoots with eachother, and Cottan advises Hunter to play along with the terrorism angle of the investigation in exchange for immunity.
The Series 1 epilogue reveals that the evidence collected by DCI Anthony Gates was never used against Hunter, and that Hunter was working as an informant for Central Police in exchange for immunity from prosecution.
Hunter is extracted from his safe house when DS Jayne Akers, his witness protection officer, contacts DI Lindsay Denton at 4th Street Station claiming there in a credible threat to his life. However, whilst en route to to the station the convoy is ambushed by DS Manish Prasad and DC Jeremy Cole, who kill Akers and the two uniformed officers (PS Alex Wallis and PC Vincent Butler) also accompanying them. Hunter is shot multiple times, and then set alight after the car is doused in petrol. However, he is just able to exit the vehicle.
Severely injured from bullet wounds and being set on fire, Hunter is placed in the Intensive Care Unit of South Central Hospital under armed guard for treatment. His condition improves and he almost regains consciousness before a second successful attempt on his life is made. Disguised as a nurse, DC Jeremy Cole distracts the armed officers outside Hunter's hospital room, then enters and attempts to kill him by injecting air into his IV line. Although confronted by AC-12 officers DS Steve Arnott and DC Georgia Trotman, Cole gains the upper hand and completes the action, killing Hunter.
In a flashback, it is revealed that despite being in protective custody, Hunter is still carrying out his criminal activities. DI Lindsay Denton observes him and DS Manish Prasad abusing Carly Kirk. However, when she confronts him in a car park, she is accosted by DS Jayne Akers and, previously unaware Hunter was in witness protection, backs off. Akers later visits Denton at her home and expresses her disgust with Hunter's actions. The two conspire to have Hunter kidnapped from their custody by his criminal associates, so he will no longer be able to harm people like Carly. However, it is revealed that the idea of the "kidnapping" was encouraged and orchestrated by DI Matthew Cottan, who was working in AC-9 Witness Protection at the time, and would stand to be revealed as a mole should Hunter survive. Cottan then orders Prasad and Cole not to kidnap Hunter, but to kill him and the accompanying officers (including Akers) to cover his own tracks.
Hunter's name appears on Danny Waldron’s list, alongside notable public figures such as Councillor Dale Roach and Chief Superintendent Patrick Fairbank, as individuals who played a part in the sexual abuse that took place at Sands View - reinforcing the belief that his actions were enabled by corrupt police officers.
Tommy is mentioned by name to John Corbett by Lisa McQueen. McQueen informs Corbett that it was Hunter who ran the Organised Crime Syndicate before his time, and was killed for becoming an informant for Central Police.
Hunter is revealed to be a "most likely" blood relative of Acting DSU Joanne Davidson, which strongly points her to having links with the Organised Crime Group. DNA analysis points to a high probability that Tommy Hunter is both her uncle and father based on the "unusually high percentage match and runs of homozygosity".
It is also revealed that in 2003, Hunter used his connections within Central Police to have DCI Marcus Thurwell purposefully sabotage the investigation into the attack and subsequent death of Lawrence Christopher, a young black architect who was beaten in a racist attack and later died due to police inaction. This was due to his son, Darren Hunter, being one of the attackers. Other officers involved in the corrupted investigation were then DC Ian Buckells and then Inspector Philip Osborne. The sabotaged investigation resulted in all the attackers being released and given anonymity by the Crown Prosecution Service when there was insufficient evidence to charge them.
In a presentation given by DC Chloe Bishop, an excerpt of Hunter's criminal record is shown. It shows that he was arrested on suspicion of Attempted Murder in 1995 in Kingsgate, Assault Occasioning Actual Bodily Harm (ABH) in Edge Park in 1998 and Armed Robbery in Edge Park in 2000. All proceedings were discontinued by the Crown Prosecution Service due to insufficient evidence to charge. This ties back to the conversation he had with DCI Anthony Gates in Series 1, where he confidently asks the detective to guess how long anybody has ever been able to hold him in a police station.
It is revealed by DSU Joanne Davidson that she knew Hunter as her uncle, although it is later revealed to her shock by DI Steve Arnott that he was also biologically her father. Samantha Davidson had never revealed that it was Hunter who raped her, instead telling her daughter she was raped by an unknown police officer when she was 15. Hunter would remain uninvolved in his sister and daughter's lives for over a decade, whilst they remained in Glasgow and he solidified his position in the Organised Crime Group within the West Midlands. However, in 1995, after discovering that Joanne was doing well academically and had never been in trouble with the police, he groomed and forced her into returning with him to the West Midlands to join Central Police as a mole for his organisation. As she had never lived in the area previously, her links to familial criminality would be unknown and unlikely to be discovered. Davidson joined in 1999 after undergoing training at Melton Police College. He would later do the same with Matthew Cottan, a teenager who worked for him as a caddy in the Edge Park Golf Club.
Davidson further reveals that after Hunter was arrested in Series 1 the Organised Crime Group began to splinter, eventually leading to Hunters murder (alongside DS Jayne Akers, PS Alex Wallis and PC Vincent Butler) in Series 2, organised by Hunters other mole DI Matthew Cottan. She then alludes that a new senior figure affiliated with Central Police took control of the mantle of the organisation, but refuses to name him.