Can sibling victims and perpetrators live together?

Help! My question is, has anyone been successful in parenting siblings in which one was a victim of sexual abuse and the other was a sexual perpetrator, where the child who had been victimized felt safe and was able to thrive together in the home? (even if the victim's perpetrator was not the sibling in question) Here is a little more info on our situation specifically, sorry it is kind of long. I adopted a sibling group of three children who were placed with me at the ages of 6, 9, 10, now they are 10(g), 13(g), 15(b). The children were removed from their home at 4, 7, 9 due to sexual abuse by their teenage brother (not placed with me) and later we discovered that both bio parents had also molested them. My youngest was sexually reactive and RAD, my oldest is mentally retarded, non-verbal, and began having sexually reactive behavior at the start of puberty. The youngest has made amazing strides, is no longer acting out sexually, has worked through all of that in therapy, and is healed from RAD. The oldest was placed in a residential center a little over a year ago due to his behaviors which were becoming more persistent and which we were unable to curb. Over the last year, my oldest is doing well in the RTC, has had no sexual behaviors in the last 10 months, and the state is planning to cut funding in a couple of months and expects him to reunify. Honestly, other than the sexual behaviors (non-aggressive, but sneaky and purposeful), he is a super great kid - kind, helpful, sweet, responsible, the whole package. Problem is, with his mental limitations, it is hard to know if he is actually capable of truly separating himself from those behaviors. Other problem is that my youngest has been having increasing behaviors. It is hard to tell if it is related because she is still kind of a roller coaster, but may be related since we have started her brother on visits home. She states that she wants him home, was upset when he had to leave, etc. She was the first and most vocal about her victimization by her oldest brother and her birth father and her testimony led to them being removed from their birth home. I don't believe she was ever victimized by her brother-my oldest son. I caught his behavior early, and from that point on, caught any attempts before they materialized. My oldest daughter has disclosed consensual (and some directed by birth parents) contact between her and my son prior to them living with me, however my youngest has denied that she experienced anything of the sort. In sand tray therapy last year, her depictions of her brother were menacing, dark, and scary. She has never vocally expressed any fear of him. Recently, she framed him for a behavior that would have had serious consequences for him, she says it was just her trying to stay out of trouble and she has no fear of him. Obviously, we have some things to work through on our end before he can come home! Aside from anything else, it just hits me that my girls were molested by a teenage brother once, and now they are facing living with another teenage brother who has been (and carries potential to be again) a sexual perpetrator. I believe that I can provide supervision and supports that will ensure physical safety in the home if we were to attempt to bring him home; it is the emotional safety piece that I am most concerned about. So, again, my question is, has anyone been successful in parenting siblings in which one was a victim of sexual abuse and the other was a sexual perpetrator, where the child who had been victimized felt safe and was able to thrive in the home? (even if the victim's perpetrator was not the sibling in question)