How to respond if someone tells you they’ve been raped or sexually assaulted

This offers some good pointers.

http://www.theguardian.com/commentisfree/2015/jul/29/sexual-assault-rape-how-to-respond?CMP=fb_gu

I've been in the position where someone confided such a report to me, the most frustrating thing is hearing they feel ashamed and won't report for that reason. All I could do was just be there for them in the silence, sometimes that is all you can do.

Just listen and be supportive.
Ask the person what might assist them in the moment.

The best thing you can do is to listen with no judgement.

Promote understanding and compassion.
try to offer support in them reporting the crime and getting help.

No judgments.

As an assault survivor myself; the best thing you can do is empathize; be kind;acknowledge the difficulty that person is going through; the strength they have for telling someone- because it does take a lot of strength to be so vulnerable.

Offer help; be compassionate; and no judgments.