Utah cops say Kouri Richins' mom may have been involved in planning son-in-law's poisoning after he died from drinking fentanyl-laced Moscow mule

Utah cops have revealed that the mother of accused killer Kouri Richins may have been involved in her son-in-law's alleged murder. 

Richins, from Kama in Utah, is accused of poisoning her husband by serving him a fentanyl-laced Moscow mule on March 3, 2022. 

Now investigators have revealed a new theory that Richins got the idea from her mother Lisa Darden, 64. 

In May 2023, a Summit County Sheriff's Office detective submitted a search warrant affidavit based on a suspicion that Darden was 'involved in planning and orchestrating Eric's death,' based on her previous involvement with a mysterious death in 2006.

'In investigating Kouri Richins' associates, it was discovered that in 2006, Richins' mother, Lisa Darden was living with an adult female with whom she was having a romantic relationship,' the detective wrote in the affidavit.

'In April of that year, her romantic partner died unexpectedly.'

Kouri Richins is accused of poisoning her husband Eric, 39, by slipping him five times the lethal dose of fentanyl into a Moscow Mule in March 2022

Investigators have uncovered evidence suggesting that Richins' mother Lisa Darden, 64, (pictured) may have played a role in Eric Richins' death

The partner was Gertrude Lee Moore, who died at the age of 49 'suddenly' on April 30, 2006. In Moore's obituary, Darden was described as 'her best friend.' 

An autopsy revealed that Moore's 'immediate cause of death was a drug poisoning from an overdose of oxycodone,' Fox News reported.

'Further investigation showed that Lisa Darden had been named as the beneficiary of her partner's estate a short time before her death,' the detective continued. 

'The female did have current prescriptions for oxycodone and reportedly struggled with abusing her meds. She, however, 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.'

The detective suggested that, based on Darden's proximity to Moore's suspicious overdose death and her close relationship with Richins, she could have been involved in 'planning and orchestrating' Eric's overdose death.

Skye Lazaro, the attorney representing Kouri Richins, denied the detective's suggestion and said Darden's partner was a victim of the national opioid crisis.

'Summit County is well aware that opioid addiction and fentanyl overdose is a rampant problem throughout the country. According to the CDC, 150 people die every day from overdoses related to synthetic opioids like fentanyl,' Lazaro said in a statement to Fox. 

Skye Lazaro, the attorney representing Kouri Richins, denied the detective's suggestion that the mother was involved and said Darden's partner was a victim of the national opioid crisis 

Richins is accused of poisoning husband Eric (pictured right), 39, by slipping him five times the lethal dose of fentanyl into the drink in March 2022

The night that Eric died, the mother and daughter were celebrating Richins' recent closure on a $2 million mansion. Richins owned a real estate company and her husband owned a successful masonry business. 

One day after his death, affidavits for search warrants show that Kouri signed the closing papers on the property and invited friends for a party where she was drinking and celebrating.  

Richins and her husband had previously been arguing about her plans to purchase and flip a 10-acre $2 million home in the days before he was found dead at their Utah home last March, according to court documents.

Prosecutors say Eric found out that his wife had taken out a $250,000 home equity line of credit and spent it, withdrawn $100,000 from his bank accounts, and spent more than $30,000 on his credit cards.

Kouri Richins also stole about $134,000 from her husband's business meant for tax payments, the documents state.

The documents state that she agreed to repay her husband back when he confronted her about the missing money.

Prosecutors allege Kouri purchased four different life insurance policies, which totaled over $1.9 million between 2015 and 2017.

Kouri, now 35, was charged with aggravated murder and drug possession in 2023. Authorities claim that she poisoned Eric with fentanyl to collect millions in life insurance funds. 

Kouri is said to have bought four life insurance policies on her husband totaling $2million in the years prior to his death, according to court records

Richins and her husband had been arguing about her plans to purchase and flip a 10-acre $2 million home, pictured here, in the days before he was found dead 

Prior to his death in March of 2022, Eric had changed his will to make his sister the sole beneficiary of his life insurance policy and was even thinking of getting a divorce from Kouri, according to his family.

Family attorney and spokesperson Greg Skordas previously told DailyMail.com Eric was afraid Kouri was trying to kill him after two separate instances in which he became violently ill after drinking or eating with his wife. 

Darden told the broadcaster: 'I believe Eric may have gotten pain pills and didn't realize that they had fentanyl in them.

'If you knew Kouri, she would never ever do this. Not only to Eric, but to those boys.' 

Her brother Ronnie also told the show: 'She loves her boys way to much to take their father away from them.

'They were in probably the best spot we've seen them in in a long time at the time of his death.'

The family also claimed that Eric 'loved to party', with Ronnie adding: 'Eric loved to party, he loved to have a good time.

'The simplest answer is often the correct one, it was most likely an accidental overdose.' 

Darden previously said Eric, who came from a prominent Mormon family in Kamas, would cheat on his wife and left her with a black eye after she confronted his alleged former mistress.

She identified the mistress as Jennifer White, 40, who like Eric worked in the masonry business.

Darden said her daughter grew suspicious when her husband's phone rang at home. She picked it up, and the woman on the other end instantly hung up.

Richins quizzed her husband, who confessed to the affair, according to Darden.

It is claimed that Richins then phoned the alleged mistress the next day, shouting at her and demanding she leave her husband alone, the mom said.

'Eric responded angrily, and this wasn't the first time,' Darden said. 'He'd push her, he'd punch her.'

Darden also claimed Eric would cheat on his wife and identified his mistress as Jennifer White, 40 (pictured) - who denied the affair

Richins had written a book following her husband's passing and appeared on TV promoting it

Approached by DailyMail.com, White acknowledged the confrontational call, but said she denied the affair and that was the end of it.

Shortly after her husband's death, the mother of three self-published a children's book titled 'Are You with Me?' about an angel wing-clad deceased father watching over his sons. 

She promoted it on television and radio, describing the book as a way to help children grieve the loss of a loved one.

She said in an interview that she was motivated to write the book after searching Amazon and Barnes and Noble and finding 'nothing' to help them 'cope'.

'I went on Amazon and Barnes and Noble to try to find something to help us cope at night, nights are the hardest. I just wanted some story to read to my kids at night and I couldn't find anything that suited them, so I was like "let's just write one".'