The judge's ruling came after prosecutors said in court they were "unable to proceed" at this time with the case against Goodman, 70, who had been charged with killing Alan Goodman, 80, in April.
Judge Jessica Silvers dismissed the case without prejudice, meaning charges could be brought again.
Los Angeles County District Attorney's Office spokeswoman Sandi Gibbons said the investigation remains open, the Los Angeles Times reported.
Citing sources who wished to remain anonymous, the newspaper said prosecution experts had concluded evidence could show Alan Goodman's death was accidental, as Lois Goodman has maintained.
Lois Goodman -- who had pleaded not guilty -- was accused of killing her husband at their home in Woodland Hills, Calif., and then trying to make it look like he had been killed in a tumble down a staircase.
"She bludgeoned him to death with a coffee mug," said Jane Robison, a spokeswoman for the district attorney's office, after Lois Goodman was arrested in April.
The body of Alan Goodman had already been sent to the morgue before homicide detectives or a coroner's investigator were sent to the couple's home. No homicide investigation was conducted until after a coroner's investigator reported three days after Alan Goodman died that there were signs of "deep penetrating blunt force trauma" on his head and ears, the Times reported.