Karen Read Witness Brian 'Lucky' Loughran Says She Went 'Through Hell,' Twice

Karen Read deserved to be acquitted after being put through the gauntlet -- twice ... so says a star witness in her case.

Brian "Lucky" Loughran -- the snowplow driver who testified during Read's two trials that he didn't see John O'Keefe's body lying in front of the house where the Boston cop was later found dead in January 2022 -- tells TMZ ... he's happy Read was found not guilty on murder and manslaughter charges.

Loughran tells us he always thought Karen was innocent ... and, going through last year's proceedings which ended in a mistrial, and this year's trial that ended in her acquittal earlier this week, means she "went through hell twice."

And, because of Karen's struggle, Brian feels she deserves all the TV, movie and book deals that are inevitably coming her way.

While Loughran says he's "flattered" Read's supporters think he played a critical role in helping her go free, he insists he was just doing his job ... and, he only told the truth on the stand.

ICYMI ... Loughran's bombshell testimony certainly helped Read earlier this month -- when he told the court he drove past the house multiple times, including around 2:40 AM.

He says he could clearly see the front door ... but, when asked if he saw anything lying in the snow in the front, he replied, "I saw nothing.” This would've been hours after prosecutors say Read hit and killed O'Keefe -- so, his body should've been in the yard, according to their theory.

Loughran testified to the same facts during Read's trial last year, shortly after he lost his wife ... so, he said this second time around was slightly easier for him.