Missing teen true story?

I think the movie was from the mid to late 80, possibly early 90s (but not later than 1992) pretty sure it was no-name actors. 

It follows a mother searching for her missing/runaway/kidnapped teen daughter in what I think was maybe LA or similar big city. I think the remains were found at the end, but she is stonewalled because the cops didn’t care to the ‘why’ - they’d labeled her an addict or gang member.

I believed it was a true story & I was sure the title was “not my daughter” (as in ‘she ran away but was taken in by the wrong crowd & wouldn’t knowingly do these things without drugs/coercion) - search results suggest the Sally Field movie “not without my daughter “ and it’s not that one.