[library user]

I think what Judge Judy means is that there’s typically signs long before the marriage, i.e., days, weeks, months into the relationship, long before a marriage even occurs.

[count-your-change]

Signs like: He “borrows” money from the woman, talks about how bad his “ex” is, was fired from his last job because (fill in from many excuses), is a “two beer” drunk, lost his driver's license, is rude because “that's just the way I am”, has a foul mouth around women, lacks good grooming and hygiene, his car is dirty or filled with trash.
Some of these signs might seem trivial but having seen lots of worthless debris float into women's lives I can say these are pretty good predictors of trouble ahead. And of course a similar list could be made for women.