Petr Lopatin is Viktor Yavlinsky's security commander and a minor antagonist in Syphon Filter: Dark Mirror.
How Lopatin came into Yavlinsky's employ is unknown, but what is certain is that within his booby-trapped dresser, Gabe Logan found credit cards, travelers checks, and a fake passport in the name of Harold Montague. Gabe ran this through Zeus and Teresa Lipan tells him Montague died at birth in Paris 40 years ago. Lopatin must have scoured death records until he found a baby who was born at the same time he was, but who died during child birth. He then obtained a copy of the birth certificate by claiming he lost the original, then use that certificate to get all his other ID.
Lopatin is briefly seen taunting a female prostitute. Gabe eventually kills him before he can hurt the latter. The discovery of another prostitute's corpse reveals that Lopatin was a serial killer.