A woman seeks vengeance against two men who made her life a living hell, her husband and a corrupt lawyer, but after she sets them up to kill on another, she struggles to prove her innocence when the police discover she had reason to kill them.

Leaning towards:
“An abused woman sets out to exact vengeance against her lowdown husband and his divorce lawyer [but when GOAL] she must prove her innocence”
OR
“A vengeful woman must prove her innocence when a concocted plan to have her lowdown husband and his divorce lawyer kill each comes true”

Other keywords: unscrupulous divorce lawyer.

Make this yours, keep going!

A pair of corrupt cops are determined to stop a battered wife from evading justice after she commits the perfect crime: she orchestrates her husband and a corrupt lawyer to kill one another.

Hmm. This feels a bit long. Compelling but a bit too many words to get the point across. Could you start it with "When a *adj* woman orchestrates her husband and lawyer to kill each other, one cop connects the dots and she has to stay one step ahead of him."