Rich, I interpret this statment to mean the piano was an element of the ligature strangulation.
http://www.starcourier.com/article/20140310/News/140319882#ixzz2yjD0sOk4
Heaven have mercy on the poor mother who returned home after work to be met with such horror. Some parents spend many years tortured by questions of what happened to their missing children, and others, like Mary Ann's parents, know all too well. I can't help but wonder which is worse.
When reading about Mary Ann's murder, two details in particular jumped out at me.
1. Victim tied to a piano.
2. Two forms of ligature: rope
and electrical cord.
Both are unusual, and indicate planning and forethought. The electrical cord might've been one already in use in the home, but more than likely the rope was brought to the scene by the killer.
Actually the use of the electrical cord seemed to indicate it wasn't a planned, event. However I believe though the origin of the rope is unknown at this point , so it may've come from the same house.
Though its entirely possible that the killer brought the rope, and didn't have enough, which would indicate unfamiliarity with that type of action. And present a mixed, scene in terms of behavior
Then tying the victim to the piano, that seems very personal to me. If nothing else, the killer had to know he would have time to complete the act. It's no wonder the consensus back then was that the killer knew the family, and was aware both parents were at work. Yet, from what I've read, LE didn't turn up any strong suspects. I'd be looking at a peer acquaintance, a teacher, a co-worker of either parent, or someone who recently had done work inside the home, like a painter or a plumber.
In ANY homicide of a child PARTICULARLY one inside a home, where they reside, you investigate the family 1st . This is especially true if there's any history of the child being injured, whether they were initially cleared, or not.
Unfortunately sometimes parents & siblings, kill children.
You interview, anyone and everyone, you come across, in connection to the victim.
Next you look to see what type of crimes, were committed in the area.. any break ins, burglaries, any robberies, any sexual assaults?
Forensically, depending on how intricate her bindings, were you could speculate (I hate to use that word here) her killer was comfortable within the residence , indicating some familiarity with the residence, and the victim, OR you can make the assumption (again hate to "assume" anything) he was in a panic, and grabbed whatever he could to bind her to the piano, after beating her.
There are some elements of this crime, that seem "staged" to throw off the investigation, though without the actual reports, and crime scene photos.. again speculative
You would need to determine 1) Was she tied THEN beaten.. IE Any cast off blood, on the outside of bindings, and surrounding area, where she was found, or 2) was she beaten, THEN tied to the piano- IE blood on the inside of he bindings, but not in the immediate area in which she was found
This would show 2 very distinct, differing Offender behavior patterns
Though its possible her attacker strangled, her and then set it so it looked as if her positioning, caused, her to die of strangulation, If the report of the binding causing her death is accurate, you might even call her death "accidental" (in terms of how she actually died)
As to the question of sexual assault, it's jmo, but what I've come to realize after researching hundreds of older cold cases, unless it's stated that no sexual assault occurred, it's safe to assume it did. It just wasn't the norm at the time to report it, especially when the victim was a minor. On the other hand, in the cases of prostitute vicitms, rape/sexual assault often was overstated to sensationalize the story. Some might disagree, but that's my impression, fwiw.
Figures, and that would be a key piece of evidence, in determining motive.
