I certainly can't speculate as to the mindset of the other victims, but what we've experienced in cases in which we've had multiple victims with the same offender is that once information comes to light that this individual has been charged and will be tried for sexual offences, other victims at that time are more comfortable coming forward because they believe their story will potentially have more weight. It's also quite possible that their recollection of events becomes much more solidified after hearing others come forward, as they recall what's occurred to them. They think, “this possibly is an offence and I need to come forward and speak to the authorities about this”.
On May 27th, 2014. See this statement in context.