1.Small. Hardly different from the prior, which is dominated by the probability that someone in whatever reference class you would have put Amanda into on January 1, 2007 would commit murder within twelve months. Something on the order of 0.01 or 0.1 at most.

What information do these new priors reflect? Obviously 1-10% of upper-middle class female college students with no history of criminal activity won't commit murder over the next 12 months so I assume that these priors are taking something else into account- like the fact that she lived with a murder victim. But can you say what else you've included? (Or point me if you already have somewhere).