This is also a breakdown in judicial and jail procedures. In addition, from a handful of such cases I recall over the years, the defendants tend to be not very bright.
Exactly correct. There is also the problem of overworked jail personnel just refusing to listen to people in jail. It is a sort of “they are all liars” and “they deserve to be here” and “not my job” all rolled into one.
Lots of jails have way more people in them than they were ever designed to handle.