A man from Minnesota has been accused of murdering his roommate at a sober living facility in June, using thallium as a weapon. This charge came about after investigators found evidence of his multiple online searches and purchases related to the extremely poisonous metal.

Stuart Hanmer, aged 35, is charged with second-degree murder, signifying intent but not premeditated planning, in relation to the death of Cody Ernst, 33, on June 22, according to InForum.

On May 15, Ernst experienced severe symptoms such as fainting, vomiting, dizziness, and nausea, which he relayed to his fiancée. The following day, she discovered him unresponsive in the bathroom and immediately called emergency services.

Ernst was admitted to the hospital showing signs similar to seizures, as noted in a police report. He left the hospital against medical advice but was soon readmitted. Eventually, he was transferred to the University of Minnesota Fairview, where tests confirmed thallium poisoning. Ernst passed away there on June 22.

Doctors said there was no way Ernst could have been exposed to the level of thallium in his system from environmental sources.

Police in St. Cloud began their investigation after realizing that Ernst and Hanmer shared a living space. They spoke with Hanmer following Ernst’s death, during which Hanmer mentioned their routine of smoking marijuana and drinking coffee and claimed ignorance of thallium poisoning until after Ernst’s passing.

In early August, authorities conducted a search of Hanmer’s residence and seized two phones. They discovered nearly two dozen searches related to thallium dating back to early April. These searches included questions like “how much thallium nitrate is fatal” and “is thallium nitrate the most toxic,” alongside a record of purchasing 5 grams of 99.99 percent thallium metal for $85 on April 5.

The next day, he bought 10 more grams, followed by another 10 grams on May 14. That last shipment was delivered to Hanmer’s post office box, and he signed for it.

The search of the cell phones found more searches about thallium on May 14 and 15, including “how long does it take for thallium to kill you” and “do people seem to get better after initial thallium exposure.”

Hanmer also watched a video showing how to make thallium sulfate.

According to the Brainerd Dispatch, thallium was previously used as a rodent killer and insecticide but was banned in 1965. It has some use in industrial applications, including as a component in infrared optics and high-temperature superconductors.

The paper said that Ernst had lived at the sober house for several months, and Hanmer moved in in early May. It did not say if the two knew each other prior to Hanmer moving in.

Hanmer was arrested last week and booked into Stearns County jail, InForum said.

He was already awaiting sentencing after pleading guilty on August 18 to a felony domestic violence charge in which he threatened to stab an ex-girlfriend with a needle and violated an order of protection against him.

He was previously convicted of assault in 2023 and domestic violence in 2017.

Court documents did not say why Hanmer wanted Ernst dead.