SIOUX FALLS, S.D. (AP) — The trial for a woman accused of killing her newborn son 40 years ago has been delayed again.

Theresa Bentaas' trial was supposed to start Monday in Minnehaha County court. But the Sioux Falls Argus Leader reported Friday that the trial has now been delayed indefinitely. RandySample of the Minnehaha County State's Attorney's Office said both sides agreed to a postponement and a new start date hasn't been set.

Bentaas, 58, is charged with murder and manslaughter in the 1981 death of the infant found abandoned in a cornfield ditch in Sioux Falls. The baby died of exposure. Investigators used DNA to link Bentass to the newborn in 2019.

The postponement marks the third delay in her trial since she was charged in March 2019. The parties in September 2019 said they were having trouble finding times when all witnesses were available. Bentaas' attorney delayed again this past November, citing a rise in COVID-19 cases.