Sometimes, instinct does not work well. I admit there were times when you thought you knew the person too well, and you ended up being betrayed. At times, that person didn’t leave up to your expectation, or worst left a bad record.
This also happens a lot at work. Not too many companies do a background check. Some of the companies I know has a quick turn over not because people left at their own will but because that employee has done something unacceptable which the company failed to check. IIf I were an owner of any business, definitely we will check background checks now, not tomorrow, not next month. Now!