of the team, Izzy relies completely on modern policing techniques, an asset valued highly by DAC Donald Bevan. When Bevan's attempt to hire Sandra Pullman onto S010 fails, he pulls Izzy out of UCOS and instead offers him a place training with a firearms unit.. DI Greg Johnson DI Greg Johnson (Patrick Baladi) (2004): Greg is a member of Special Branch who tries to prevent UCOS from finding out uncomfortable truths about the death of peace protestor Josh Livesey at a NATO base in the UK in 1984. However, Greg later helps the team in the investigation by admitting the involvement of Special Branch in disposing of Josh's body and the murder weapon to avoid harmful publicity but denying Special Branch's responsibility for the killing, leading UCOS to the real murderer. A mutual attraction between Greg and Sandra led the two to begin a relationship, which became more serious over several months. However, the relationship later ended and Greg is not seen again beyond the first series. Dr. Steven Lilwall Dr. Steven Lilwall (Adam Howden) (2008-2009): Lilwall works as a forensic scientist for the Metropolitan Police and supports the team across two cases. The first, an investigation into the death of a brewer at a brewery, sees Lilwall develop an antagonistic relationship with the UCOS team due to his smug manner and penchant for showing off about his forensic findings. As a result, he gets into a physical altercation with a drunken Gerry, forcing Sandra to make Gerry apologise for giving Lilwall a black eye. Lilwall returns a year later to support the team whilst investigating the murder of a timeshare salesman, during which Gerry continues to have an antagonistic relationship with him. DCS Frank Patterson DCS Frank Patterson (Phil Daniels) (2009–2010): Patterson is a short-tempered, old-fashioned copper, a former police colleague of Gerry's. He and Gerry fell out over a woman. They reunite when Frank is interviewed over an investigation of the disappearance of two student activists, which leads to UCOS's old enemy Ricky Hanson. Frank provides information crucial in Hanson's arrest for killing the activists and then assists in securing his conviction for the attack on Mary Halford. Frank returns to have the team reinvestigate an armed robbery and several murders in the 1980s—he suspects that a now senior officer might have tipped off the robbery's ringleader for a cut and then conspired to cover it up. DI