Liam James Hammond is the illegitimate son of Frank Tate and half brother of Chris, Zoe and James Tate. Frank once romanced Liam's mother and in early 1961, when she was expecting, Frank left her, and she bought Liam up in poverty. Frank was a rich businessman and later married and had more children, who lived the life of luxury.
In September 1999 Liam kidnaps his employer Chris Tate. Nearly a month into his kidnap Liam reveals to Chris that Frank Tate is his father, making them half brothers. Liam shows Chris a photo of Frank with his mum plus other documents. They begin to form a bond which Chris hopes that will stop him from being hurt. In November Zoe starts to suspect that Liam is somehow involved in Chris' disappearance, as Liam seems to unusually know a lot about Chris, and seems to talk of him in the present tense. Zoe sets Liam's run to Portsmouth to get him out of the way so she can investigate but her plan backfires when Liam smells a rat and switches his run. Zoe goes to his house and rescues Chris, and is confronted by Liam, and later on, she fatally shoots Liam in the process. Zoe is stunned. Her and Chris then destroy all evidence that Liam was Frank's son, ensuring the police would have less reason to question his death. Chris, who has some doubts over whether Zoe needed to kill Liam, buries him near Frank's grave, deeply upsetting her. On the day of his funeral, D.I. Derek Spalding keeps watch on Zoe and Chris from afar.
DI Spalding confronted Chris and Zoe after the funeral, as he suspected that Liam's death was not an accident, and that he may have been another secret Tate family member with a grudge, whom Zoe finished off. Chris said that Spalding will never know, making Spalding more suspicious. However, Spalding and other members of the police were unable to prove this, and Zoe walked free.
- Liam's birth date is somewhat unclear. Liam celebrated his birthday with Chris and Zoe Tate on the 4th November, but his gravestone mentions his birth date as 9th August. To add to the confusion, when Zoe was checking Liam's CV on the computer, his birth date was given as 13th October 1959.