The lesbian lover of Kouri Richins’ mom was found dead and foaming at the mouth in a “suspicious overdose” 20 years before Richins fatally poisoned her husband with fentanyl, according to a report.

Authorities in Richins’ Utah case unearthed that her mother, Lisa Darden, was probed in 2006 for possible involvement in the death of her lover Gertrude Moore – a fact which led them to investigate whether Darden may have helped her daughter, according to a report by the Daily Mail.

Kouri, 35, was convicted Monday of slipping five times the lethal dose of fentanyl into the Moscow Mule cocktail she gave Eric, 39, on March 4, 2022, as part of a plot to try to inherit his $4 million estate and run away with her handyman lover.

The circumstances were similar enough to Moore’s demise that authorities investigated Darden, with Detective Jeff O’Driscoll noting in a search warrant that the 66-year-old “had been named as the beneficiary of her partner’s estate a short time before her death,” the outlet reported.

“Based on Lisa Darden’s proximity to her partner’s suspicious overdose death, and her relationship with Kouri, it is possible she was involved in planning and orchestrating Eric’s death,” O’Driscoll wrote in the warrant.

He also said that since Moore was actively addicted to oxycodone, “this would likely rule out the possibility of an accidental overdose.”

Moore was found with foam in her nose and mouth.

Despite police searching Darden’s Francis, Utah, home, they were never able to find any evidence connecting her to the more recent crime.

She was not charged in either case and is not accused of wrongdoing.

Richins notably wrote a children’s book on grief about a year after her husband’s death. She went on local tv and radio stations to promote the self-published book entitled, “Are You With Me?” which she said she penned to help her three boys understand loss.

Months later Richins was arrested for the murder.