The gun possession case against Dorothy Hirsch, the estranged wife of “Duck Sauce Killer” Glenn Hirsch, should be thrown out because of new DNA evidence, her lawyer argued in a just filed letter.

“The DNA results demonstrate that nothing links Dorothy to the firearms Glenn Hirsch stored among the possessions he put inside of black garbage bags and boxes which he then stuffed in a hallway closet,” lawyer Mark Bederow wrote in a letter to prosecutor Thomas Salmon, which was filed Saturday in Queens Criminal Court.

A grand jury in September indicted Hirsch, 63, on weapons possession charges after police found a cache of firearms in her Briarwood home.

The Hirsches had lived apart for years.

Glenn Hirsch shot to death deliveryman Zhiwen Yan on April 30 in Forest Hills, apparently over a beef with the Great Wall restaurant shorting him on duck sauce. Hirsch then killed himself on Aug. 5 while awaiting trial.

He wrote in a suicide note that his wife didn’t know about the guns in her apartment.

Bederow told The Post there was only enough DNA on two of the weapons to be tested.

Results from the Medical Examiner’s office show one sample was 93.7 times more probable to have come from someone other than Dorothy Hirsch and the other was not linked to her, according to a report submitted to the court.

“Practically speaking it’s not her,” Bederow said. “She did not know what Glenn was storing in a closet that was used exclusively by him and filled from floor to ceiling with his junk.”

Bederow previously filed a motion to dismiss the case. A court filing claimed Glenn Hirsch subjected his wife to years of abuse.

A spokesman for the Queens District Attorney’s office said it does not comment on pending cases.