Lindsay Clancy Juror Says He Had No Reasonable Doubt, Believes She's Guilty

The holdout juror in the Lindsay Clancy case is calling BS on claims that he had reasonable doubt ... insisting he's convinced she meticulously planned to kill her kids.

Michael Péguy Desronvil is speaking out personally for the first time ... trying to clear up confusion about what went down in the jury room of Lindsay's murder trial that ended in an 11-1 deadlock.

In a statement to TMZ, Desronvil said, "I didn't have any doubts. As I tried to explain different possible theories during deliberation, I kept getting cut off as if I had doubts based on the evidence presented."

He goes on, "Based on all the physical evidence, key witnesses, and what the prosecution presented, I thought it was enough proof that she (Clancy) knew exactly what she was doing and planned."

Another juror -- Paula Devlin -- has said that she went as far as filling out verdict sheets after Desronvil allegedly admitted he had reasonable doubt ... before he said something to the effect of "But I'm still not going to say that she's not guilty by reason of insanity."

Nick Dargie -- a third juror -- said Desronvil couldn't show any evidence to support his position or describe witness testimony that backed his deliberation room claims.

While this is the first time Desronvil has spoken himself publicly ... Ray Marcel of "Fugitive TV" has already relayed what the juror told him in a NewsNation interview Wednesday -- explaining Marcel "felt that she was sane by the preparation she did."

Desronvil had been blasted by Kevin Reddington -- Lindsay's attorney -- even before his name came out ... with the lawyer thanking the 11 members of the jury who wanted to vote not guilty by reason of insanity, and only those 11 jurors, after the trial wrapped.