Our legal system is very weighted towards the defendant. Having done jury service, I am now not suprised that the conviction rate in sexual assault cases is so low.
It was made very clear by the judge that we all had to be '99.9%' sure to return a result of guilty. Some of us were that sure, some were 'quite sure' 'nearly sure' but not 99.9% sure. In the end we returned a 'hung' verdict, which meant it went to retrial, and he was convicted as defendant had sprung new info in our trial that the prosecution had no chance to investigate, but 2nd time round he didn't have element of suprise, the prosecution were able to pull his defense apart.
It's really tough to be on a jury, I had nightmares for months after that we had let a child rapist go free (I was one of those convinced he was guilty)and was so relieved when I found out he had been convicted.