I had a quick look for some statistics to verify my priors that both female on female murder and multiple offender murder are unusual. These data seem relevant: gender; multiple offenders. These appear to back up my intuition that finding a very likely male suspect (Guede) should have greatly reduced the prosecution's odds for the guilt of a female suspect (Knox) in a multiple offender attack. A plausible case for a male offender committing the crime alone should greatly lower the probability of guilt of a female suspect acting either alone or as an accomplice.