Why do you say it is unlikely to make money from real estate?
Perhaps he got the original money from somewhere else, some criminal activity. But he could have multiplied it with luck or skill in real estate market.
We have not seen that level of real estate transactions as being recorded for him. Could be, we just have not seen it.
On the other hand, paying cash for real estate is another decent way to launder money.
No it’s not. The money has to be in a bank first, which means it has already been laundered.
You can’t buy real estate with actual cash. Red flag city.
If he was lucky/smart in real estate, he could have made some decent money at that. I don’t recall seeing that he was ever married (or divorced!), or ever had children. That would have saved him thousands of dollars by the time he was 64. Also, didn’t he work for the government (IRS?) at one time? That job probably paid 3X what it was worth, and provided a huge pension after 2 or 3 years on the job. Maybe his bank robber dad left him some cash under a rock in the desert?