My best friend's mother recently had to go into a care home and her flat had to be emptied and sold to help pay care home fees. Friend has a sister who lives at the opposite end of country and, in the last 20 years, has only visited their mother a handful of times and has had no input into her 24/7 care or choosing an appropriate home for her; this has fallen entirely to friend.
As soon as sister became aware that the flat was being emptied, she arrived at their mother's flat, let herself in and cleared it of anything of value; war medals from their father, jewellery, small items of value etc. She did it within a couple of hours, saying nothing to my friend and had vanished with the everything of value before my friend even knew she'd been in the area. She left the flat in such a mess whilst she'd ransacked the place that my friend thought their had been a burglary and was about to the call the police. It was only cctv footage from the concierge of the flags that they discovered the culprit.
There's seems to be no depth too low that some people will sink where money is concerned.