//...if in court all your previous would be read out BEFORE the trial//
No, that pre-judges the case, Cinders. The jury will know[i that the accused is a a villain, shrug shoulders and find for the prosecution. But it doesn't [i]necessarily] follow that the "known"" villain was guilty in the particular case, which should be determined by evidence. Some of us remember the "George Davis is innocent" campaign whch ruined the Headingley test match. That was all about "fabricated" evidence as I recall.
But I understand your point. For a jury to acquit somebody because the evidence presented didn't meet the "beyond reasonable doubt" standard, and then to find that the man they've acquitted has a long record of similar offences would sipp some of them off, wouldn't it?
Maybe if a jury is hung, or undecided they might request the defendant's criminal history.
Don't know how the jurists might view that suggestion. They have funny principles sometimes. Take this piece of nonsense from the famous 18th century jurist stone who said "Better that ten guilty persons escape than that one innocent suffer". Why ten rather one or a thousand you might adk. The often quoted "principle" has a metaphorical decency, but, like other moral metaphors ("turn the other cheek") is impossible to apply literally without contradicting the principles they are trying to assert. The only way to guarantee that an innocent man is not charged and convicted is to prosecute nobody.