I've lurked this site for years but never joined as I didn't feel I had anything to contribute; at least not until now.
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IMHO several things about the lack of clear blood trail from suspect got me thinking about how this could happen.
IMO, the easiest answer could be to utilize PPE like <modsnip> in the hospitals. Pre-Covid, all the surgical PPE was back in the OR and more difficult for a random employee to take home. Post-Covid, it became more acceptable to leave surgical PPE on the hospital floor or to see someone pop into the OR to grab a suit, gown and hood before heading back out to the floor.
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The suspect could have used the following PPE to make for a fast and easy escape.
-Biohazard body suit (we call them bunny suits)
-Surgical gown
-Shoe covers (extend up to. the knee)
-Surgical helmet (basically a hood with built in face shield that tucks into bodysuit.
-double gloved hands in surgical gloves.
-securely tape seams where: pants of jumpsuit meet top of shoe cover, gloves meet sleeves, helmet may or may not need tape.
This can all be gotten for free from a hospital if he were to work at one. One could also buy the pieces online. A lower quality (but still effective) kit could range from $100-$300. Could even be found cheaper perhaps.
So,the perp could have come dressed in PPE, or, they could have come in normal clothes and then dressed the PPE over their "getaway" clothes. Once dressed, he goes in and commits the crimes. Blood is everywhere. He pulls PPE off, bags it up, and walks out in normal clothes without any blood on him. The PPE would also prevent his hair and skin from being found at the crime scene. He may have a bruise if someone fought back, but would likely not have any cuts, scratches, etc. so I would expect minimal DNA evidence to be found.
This is all only my opinion of course. It would require some planning to pull off. It could just as easy be a psychopath who just undressed prior to the murders then showered, got dressed and left without any blood trail.
Hopefully for the families they get their answers soon .