I believe you. I can even guess the story.
In the late 80s/early 90s a staff member (self taught in office/access) quickly threw together something at the request of a manager as a stop gap wile a new proper system was specked out.
The person learned as they went and the system grew in functionality and complexity until the term spaghetti code was a massive understatement. It became their job.
The new proper system never arrived and they have been making do for the past 30-40 years.
I ran into the same thing a decade or so ago and it was a nightmare, but it was just an ice cream franchise, not prison related
I know, I have seen them.
I was sysadmin for a Bankruptcy and Insolvency Firm for more than a decade and walked into 100s of businesses on the point of failure. Many of them could not be saved simply because their systems were so bad it was better for a buyer to buy their equipment and start with a clean sheet.
The ice cream business was going under because the partner who had been the access self starter had an argument with the others and had walked out 18months ago.
The access system ran the entire business (accounting and wages were on other programs but the db feed them data) and he was the only one who had any idea.
Shit started to go wrong and they had no idea what to do.