The reason for my question and concern is that if these people generally have criminality in their background—and I acknowledge that some don't, but many of them do—I'm sure the defence lawyers would argue that they lack credibility or they can't be trusted. But obviously some judges in the United States haven't been swayed by that argument if their testimony is used to convict, and it sounds like the percentage of convictions is quite high.
Can you give me some context of that? What's going on there, where people come from backgrounds of high levels of criminality in many cases and their testimony is still relied upon by the courts?