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. They begin to form a bond which Chris hopes that will stop him from being hurt. In November 1999 Zoe starts to suspect that Liam is somehow involved in Chris' disappearance. Zoe sets Liam's run to Portsmouth to get him out of the way so she can investigate but Liam smells a rat and switches his run. Zoe goes to his house and rescues Chris, fatally shooting Liam in the process. They then destroy all evidence that he 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.
The police 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. 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 14th October 1959.