Getty Composite

Diddy 's ex-girlfriend Gina Huynh -- Victim No. 3 in the federal indictment who went MIA in the criminal case -- just went to bat for him in his bid to get out of jail pending sentencing.

In new legal docs, obtained by TMZ, Gina pens a letter to the judge in Diddy's criminal case ... supporting Diddy's motion for bail. Document Launch Doc

Gina says she's known Diddy for years and that she's mostly seen him as a father, family man and business man ... not a criminal.

She says their relationship had its ups and downs but says when Diddy made mistakes he was willing to acknowledge them and make better decisions moving forward. Gallery Launch Gallery

Gina says Diddy became a better person and by the time their relationship ended he "embodied an energy of love

See Full Page