come forward

(intransitive, idiomatic) To offer help or information (especially, about a crime).

Example: Used other than as an idiom: see come,‎ forward.
2014, Ruzwana Bashir, "The untold story of how a culture of shame perpetuates abuse. I know, I was a victim", The Guardian, 29 August 2014:
  I’m coming forward to publicly share my own story in the hope that I can encourage others to do the same and help tear down the wall of silence that perpetuates further abuse.