Robert Brown|A poison expert researched this drug before his wife died from it. Now he's facing prison.

A former Mayo Clinic resident and Robert Brownpoison specialist in Minnesota has been charged with murder after he allegedly gave his wife a fatal dose of a drug he had been researching online, court records say.

Investigators say Connor Bowman, 30, intentionally poisoned his wife, Betty Bowman, a Mayo Clinic pharmacist, with colchicine, a medicine used to treat gout, after days of researching the drug, according to a complaint filed in Olmsted County District Court. After her death, Connor Bowman attempted to obstruct an autopsy and demanded that she be cremated, police say.

Investigators began looking into the case after a medical examiner raised concerns about Betty Bowman's death, on Aug. 20, and its suspicious circumstances. Four days earlier, she was brought to the hospital with “severe gastrointestinal distress and dehydration where her condition deteriorated rapidly,” the complaint says, adding that her colon was removed and she experienced cardiac issues and organ failure.

Meantime, Connor Bowman told medical staff his wife was suffering from a rare immune condition called hemophagocytic lymphohistiocytosis or HLH, which hospital tests did not substantiate. Connor Bowman told multiple people his wife died of HLH and included that in her obituary, the complaint states.

Connor Bowman searched online for drug that officials say killed wife

After his wife's death, Connor Bowman said her autopsy should be canceled and allegedly told the medical examiner her death was natural, records show. He ordered that his wife be cremated immediately, which the medical examiner prevented before determining Betty Bowman died of toxic effects from colchicine, the gout drug, and the marked then manner of her death as homicide.

A search of Connor Bowman's computer history yielded research on colchicine, including calculating the lethal dosage for his wife's weight a week before she was hospitalized, the complaint states. He also looked up whether internet browsing history could be used in court as well as sodium nitrate, a chemical compound that can limit oxygen transport through the body, records say.

Connor Bowman and wife were weighing potential divorce, police say

Detectives spoke with a woman who said Connor and Betty Bowman were in the midst of divorce discussions because of "infidelity and a deteriorating relationship," a complaint says.

Police also learned Connor Bowman was the beneficiary of his wife's life insurance policy with a payout in the hundreds of thousands. At his house, investigators found a bank deposit receipt for the amount of $450,000, records show.

In response to questions about Connor Bowman's time at the Mayo Clinic, the world's largest nonprofit medical group practice, spokesperson Amanda Dyslin told USA TODAY, "We are aware of the recent arrest of a former Mayo Clinic resident on charges unrelated to his Mayo Clinic responsibilities. The resident's training at the Mayo Clinic ended earlier this month."

Dyslin did not say why Connor Bowman's training ended.

According to the complaint, Connor Bowman worked as a poison specialist and answered calls about poisons using devices issued to him by the University of Kansas. Police found that Connor Bowman had researched colchicine on his university-issued laptop, records said. A woman at the university told investigators neither Connor Bowman nor any other employees had received calls about the drug.

He remains in the Olmsted County Adult Detention Center as of Wednesday. It's unclear whether he will hire a private attorney or will be represented by the public defender's office. The public defender's office did not immediately respond to a request for comment.

Contributing: The Associated Press