EXCLUSIVE

The LAPD has finally tracked down the woman Playboy Playmate Dani Mathers body shamed and they'll ask prosecutors to nail her.

We've learned the woman -- in her 70's -- wants Mathers to feel the full force of the law for taking a pic of her while she was changing clothes in the locker room of an LA Fitness. The woman is more than willing to testify and cooperate in any way she can to bring Mathers to justice.

As for the likely charge ... we're told it's Dissemination of Private Images, a misdemeanor punishable by 6 months in jail. The L.A. City Attorney is reviewing the case and will make a decision soon.

The surreptitious photo shoot triggered outrage in the gym community and beyond. Mather's captioned the pic, "If I can't unsee this then you can't either."