Physical Evidence (1989) on Netflix

Extortionist Jake Farley is found strangled, and the clues lead directly to former detective Joe Paris, who insists on his innocence but can't provide an alibi. Public defendant Jenny Hudson gets the case, but has problems unravelling the case, complicated by the fact that virtually everyone hated Farley, and Paris has a few enemies as well. She rejects the prosecution's offers to plea bargain, but meanwhile the witnesses she finds are discredited or silenced, and an unidentified patrol car shadows Paris and Hudson wherever they go.