There's been interesting discussion regarding the murder weapon. I'd like to address some of your theories with some of my own questions:
Most of the speculation against using the maul is our questioning Sam's degree of fitness. However, based on his appearance (which is what we're all judging him on), I see no reason to think that he is below average fitness. So the question is: could an average male swing a maul enough times to kill three people?
I think yes. Based on my knowledge of mauls, they tend to be about 8 pounds. Furthermore, my boyscout troop used mauls to split wood (although you had to do it under adult supervision). If a 12-14 year old boy can wield a maul with sufficient precision to split wood, an average adult male probably could also.
Sam's weight also makes me believe he is probably stronger than a below-average fitness male.
Another question I have regarding the ball peen hammer vs. maul preference is as from a death blow standpoint. A maul would probably only need one swing to be a death blow to a teenage girl. So, in reality, the murders could have theoretically be completed with 2 swings, then a swing when the mother entered.
A ball peen hammer also deliver a death blow, but I think it's less certain than a maul. A failed first strike would certainly awake the other person (people) in the room and cause the problem where the other people murdered would have defense wounds.
Also, the hammer is a more closed quarters weapon than the maul. The hammer is probably around a foot long, which would mean Sam would have to get close enough to the victims where, again, presumably a struggle would occur.
