Timothy Busfield Asks Judge to Dismiss Grand Jury Indictment

Timothy Busfield wants his indictment thrown out ... telling a judge the prosecutors' presentation of evidence to the grand jury failed to tell the whole story.

The actor filed papers asking a judge to toss the grand jury indictment because the state of New Mexico has "abdicated its role in administering justice" and is blindly pursuing an indictment against him.

Busfield says prosecutors are well aware of an independent investigation into the allegations against him conducted by Warner Bros. that he says found nothing to back those allegations, a lie detector test Busfield passed in which he said he never inappropriately touched one of the alleged victims, and multiple witness affidavits defending him ... but has chosen to ignore all of that.

The star says he decided to testify in his own defense in front of the grand jury ... and he claims he was treated unfairly by the prosecutor, who he says treated the appearance like "adversarial cross-examination."

As you know ... Busfield surrendered to authorities in New Mexico in January, several days after a warrant for his arrest was issued -- and he was indicted on child sex abuse charges in early February. He has denied all the allegations against him. His wife, fellow actress Melissa Gilbert, has insisted he's innocent as well.