Alan Jackson — the big-time defense attorney who represented Karen Read in Massachusetts during both her criminal trials — says he sees similarities between her case and Lindsay Clancy‘s …. especially in the controversial way both were handed a mistrial.

Jackson joined us on “TMZ Live” Friday shortly after a Massachusetts Supreme Judicial Court justice upheld the mistrial ruling … and he says the justice system in Massachusetts going after Lindsay again and failing to get a conviction would be a serious black eye.

He says he felt it was a “travesty” when Karen’s case ended in a mistrial the first time … adding he didn’t understand when the judge didn’t poll individual jurors to see if they’d come to some type of verdict.

Jackson says he also doesn’t understand why it didn’t happen here … because the precedent of the Read case was sitting right there!

As for how prosecutors might change their plans if they decide to retry Lindsay … Jackson says he doesn’t expect much difference — he still thinks they’ll be chasing a first-degree murder conviction full tilt.

We’ve reported on the story closely … Judge William F. Sullivan officially declared a mistrial on Friday amid an 11-1 deadlock — with 11 seemingly wanting to declare her not guilty by reason of insanity.

A note from the jury foreperson to the court — read during the mistrial appeal — indicates the holdout juror admitted there was reasonable doubt in the case … but essentially planned on ignoring it.

BTW … Jackson also got into public opinion in the case — and explains why he thinks the retrial’s going to be even more difficult for prosecutors. Watch the clip all the way through to hear what he thinks.