A day after Karen Read was acquitted of the murder of her Boston cop boyfriend in a Massachusetts retrial, Read’s attorney Alan Jackson is revealing he had significant doubt about his client receiving fair treatment under the law … but he’s doubling down that he had no doubt she was innocent.

Jackson went on Howie Carr‘s podcast Thursday and admitted he was nervous before yesterday’s verdict was read … but he says he doesn’t think he’ll ever run into another lawyer in his lifetime who’s ever won back-to-back murder acquittals!

ICYMI, the murder retrial of Karen Read — a former finance professor accused of killing her boyfriend, John O’Keefe, in 2022 — ended with the jury finding Read not guilty of charges of second-degree murder, manslaughter while operating under the influence, and leaving the scene of an accident causing injury or death.

This was the second time she faced trial — a hung jury prompted a mistrial last year on the same charges … and prosecutors decided to bring the case against her again, with this retrial beginning in April.

This jury did find her guilty of a single count of OUI — a misdemeanor Operating Under the Influence … but Read’s getting probation, and no jail time.

The winning attorney affirmed he knew they were going to acquit her for striking John O’Keefe with her SUV … because it simply didn’t happen.

Carr brings up how he thought they were going for “triple jeopardy” after some confusion yesterday … the jury indicated they’d reached a verdict, then officials announced there wasn’t one — minutes later, they came out and read the not-guilty pronouncements.

Jackson told Carr … “I was in enormous doubt … I never doubted what the just result should be, that Karen walks out of that courtroom through the front door, not the back. But did I doubt whether or not I could get a fair trial? About every single minute of every single day. I doubted it significantly.”