Where can I watch Girlhood online?

Its a documentary about two urban teenage girls that have been convicted of violent crimes. One girl stabbed a friend three times, the other has been arrested on multiple counts of aggrivated assault and other things.

I would like to know where to watch this documentary online, as ive tried a lot of the first search options that google has given me.

If anyone has any good sites they can throw at me, be much appreciated.

Movie was made in 2003, Director was Liz Garbus.