D.S. Parker was a police officer assisting in the investigation into Texas Longford's death in May 2013. He asked Mercedes Fisher what she had seen, but she denied seeing anything or anyone acting suspicious. The officer left, unaware Mercedes was hiding bundles of money in shopping bags on the sofa next to where D.S. Parker had been sitting.
As D.I. Bulmer questioned Texas's husband Will Savage, D.S. Parker entered and handed Bulmer a folder containing new evidence: a DNA sample indicating that Texas had Dodger Savage's DNA under her fingernails when she died. A few days later, D.S. Parker arrived with a search warrant for 3 Oakdale Drive, Flat 3 - Texas's former residence. He also re-questioned Will before leaving.
D.S. Parker was portrayed by Robert Beck, eight years before he began regularly appearing as Fergus Collins.