I believe I'd be floored too if I found out a friend of mine was a child rapist.
Pedophile and molester are such benign terms for the horrid things these people do to innocent children ... I believe you did the right thing by breaking the friendship as that will protect your daughter from being his next victim ... I also believe you need to go one step further and notify the authorities so they can make contact with this ex-friend as well, and hopefully that will also prevent him from harming other children as well.
A lot of child rapists will actually insinuate themselves into a single parent's life just so they can have access to their children, often marrying them and carrying on their vile criminal acts right under the noses and behind the backs of their unsuspecting spouses.
Atrocious & Despicable!
In the meantime, it might not be a bad idea for you and your daughter to see a counselor or therapist to help process what you're going through as I'm sure this has caused quite a shock and will help you sort it out in a positive instead of negative fashion.
Wishing you courage, hope and good healing.
Sincerely,
Pfrog!