This is really interesting information. It sounds like it was an insider to the family. Maybe an assistant. someone that knew intimate details of the Sherman's lives - routines, alarm codes etc... the killer could have chosen any day of the week since HS was busy and travelling often. Was it just luck or coincidence( I dislike that word)?
what people had access to their house daily? a housekeeper, a gardener, assistants, chef? Were security checks done and was there someone new on staff?
I followed up a bit more. Strangulation seems to be a very personal violent crime. Seems passionate even. Being restrained would suggest that there could have been multiple people. Unless a weapon was used on them to make them compliant. The belts seem deliberate to constrict and make someone look at you or away from you. Were the belts from the house or brought there?
On the robbery from the previous year, what was taken? and what had happened? specific thefts or just a break in? Could someone place surveillance in their house without them knowing?
And why in their basement? is it symbolic? Did the Sherman's use the pool area for celebrations? why there?
This is the most I know or recall, hopefully others can answer, too—
-In his book, Kevin Donovan wrote that there had been 160 break-ins in the Shermans’ neighborhood in the year preceding the murders.
-a year prior to the murders, burglars broke through the Shermans’ skylight and left before HS arrived home. We don’t know what was stolen.
-HS had an assistant that worked at the home typically every day, but had Thursday and Friday off on the week of the murders.
-They had a housekeeper and gardener that worked part-time, and from court records it sounds like the housekeeper had a key and likely knew the security code. She was surprised to find that the alarm was not armed when she entered the home on the Friday following the murders.
-they also had personal trainers and massage therapists visit the home. (Primarily for HS.)
-Kevin Donovan (KD) wrote that a thin ligature consistent with a zip tie was used to kill the Shermans, in addition to the belts used in the crime. (In his book he wrote the belts could have been the ligatures used. More recently he wrote that the thinner ‘zip tie’ ligatures were likely used to kill them. The belts may have been used to restrain them and/or stage the bodies.)
-KD wrote that both belts were new and purchased by HS from Canadian Tire. They were identical except for size. BS wore one of the belts for the first time on the day of the murders. The other belt was left on a padded bench in his dressing area on the top floor.
-HS’s schedule was easily accessible as her electronic devices did not have a password, according to KD. But KD wrote that witnesses have provided statements or evidence about the Shermans being surveilled.
-I don’t know why the pool area was chosen, but it was at the very back of the basement. The pool hadn’t been used for years, but had been spruced up as the house was for sale. Some here have suggested it may be linked to their Jewish culture (water), or because it was a pool area the crime scene and the killer could be cleaned up easily.