SALT LAKE CITY (KTVX) — An unsealed court document shows a detective has speculated that the mother of Kouri Richins could have a connection in the death of Eric Richins after a similar death occurred in 2006.

Kouri Richins is awaiting trial after being accused of poisoning her husband to death with fentanyl in March 2022. Before Eric Richins’ death, Kouri Richins allegedly took out life insurance policies without her husband’s knowledge, naming her as the beneficiary.

According to court documents, Richins’ mother, Lisa Darden, was the subject of a search warrant after investigators learned that a romantic partner of hers died in 2006 from a drug overdose. Shortly before her partner’s death, Darden was named as the beneficiary of her partner’s estate.

It should be noted Darden has not been arrested or charged with any crime as of this writing, and there is no open investigation. The results of the search warrant have not been released.

Routine part of Richins’ investigation

The court documents reveal detectives began investigating those close to Kouri Richins and her associates, including her mother. Summit County Detective Jeff O’Driscoll wrote in the search warrant that Darden’s romantic partner had died unexpectedly in April 2006.

“An autopsy report of the female partner showed that her immediate cause of death was a drug poisoning from an overdose of oxycodone,” wrote O’Driscoll in the search warrant. “Further investigation showed that Lisa Darden had been named as the beneficiary of her partner’s estate a short time before her death.”

According to the documents, Darden’s partner did not have current prescriptions for oxycodone and reportedly struggled with abusing meds. O’Driscoll noted that Darden’s partner was not in a state of recovery from addiction at the time of her death.

“Based on my training and experience, this would likely rule out the possibility of an accidental overdose,” wrote O’Driscoll.

O’Driscoll said Richins appeared to be very close with her mother, communicating with her “almost daily” for both personal matters and business dealings. O’Driscoll wrote Darden showed disdain for Richins’ husband in some of those conversations.

“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,” said O’Driscoll.

ABC4 has reached out to Kouri Richins’ defense team for comment. This story will be updated with their reply.