Law & Order S15E14 - Fluency

When nine afflicted people suddenly die, Detectives Fontana and Green discover that the victims were injected with fake flu vaccine that did not protect them, leading the police to arrest a career con man (Rob Sedgwick) who's counterfeited everything, including what should have been life-saving vaccine. But while EADA Jack McCoy is getting over the departure of ADA Southerlyn, he is joined by confident new Assistant D.A. Alexandra Borgia, who boldly promises justice to the victims' relatives that will be difficult for the prosecutor to fulfill after vital search warrant evidence is tossed out.