Timothy Busfield's Child Sex Abuse Case Dismissed Over Prosecutorial Misconduct

Timothy Busfield's child sex abuse case in New Mexico has been dismissed because of prosecutorial misconduct ... though the judge is leaving the door open for prosecutors to charge him again.

TMZ has obtained an order from a judge quashing the grand jury indictment ... claiming prosecutors misrepresented the admissibility of lie detector evidence to the grand jury.

He also says the state didn't call certain witnesses after the grand jury asked to hear from them.

In his conclusion, the judge lambasted prosecutors for failing to "act in a fair and impartial manner" and for violating grand jury statutes that are "designed to protect the structural integrity of our grand jury system."

This dismissal was months in the making ... Busfield asked the judge to throw out the grand jury indictment back in June -- claiming the prosecution has "abdicated its role in administering justice"

As we've reported ... Busfield surrendered to law enforcement officers back in January after he was accused of sexually abusing two boys on the set of "The Cleaning Lady."

Busfield released a video before he surrendered ... insisting on his innocence and saying forcefully, "I didn't do anything to those little boys." His wife -- actress Melissa Gilbert -- has stood behind him as well.

Worth noting ... Harvey and Mark Geragos were sure Busfield wasn't going to be convicted -- calling the prosecution unethical during an episode of our "2 Angry Men" podcast a few weeks after Busfield was charged.