• A Missouri man who tried to buy a highly lethal chemical weapon with the cryptocurrency bitcoin on the dark web told the would-be seller, "I plan to use it soon," federal authorities said.
• Writings found within the Columbia home of the man, Jason William Siesser, "articulated Siesser's heartache, anger and resentment over a breakup, and a desire for the person who caused the heartache to die," the Justice Department said in a press release.
• Siesser, 46, was sentenced to 12 years in prison on Tuesday after having pleaded guilty last August to attempting to acquire that weapon and to aggravated identity theft.

A Missouri man who used the cryptocurrency bitcoin to try to buy a highly lethal chemical weapon that could kill 300 people told the would-be seller, "I plan to use it soon," federal authorities said Tuesday.

Writings found in the Columbia home of the man, Jason William Siesser, "articulated Siesser's heartache, anger and resentment over a breakup, and a desire for the person who caused the heartache to die," the Justice Department said in a press release.

Siesser, 46, was sentenced to 12 years in prison on Tuesday after pleading guilty in August to attempting to acquire that weapon and to aggravated identity theft.

Siesser admitted that he tried to buy the weapon on two occasions in the summer of 2018 over the dark web, giving the seller a shipping address in the name of a juvenile, the Justice Department said. The dark web, a vast area of the internet that requires a special web browser to access, is often used by criminals to anonymize their tracks as they trade in drugs, weapons and other illegal items.

In his first try, on July 4 that year, Siesser ordered two 10-milliliter units of the chemical and paid with the digital currency bitcoin, the department said.

After the seller did not ship the chemical, Siesser tried to contact the seller, telling them, "I plan to use it soon after I receive it," according to the Justice Department.

A month later, Siesser ordered three 10-milliliter units of the weapon and paid for the order with bitcoin then valued at $150. That amount of the chemical could kill about 300 people, the department said.

Officials said a controlled delivery of a package that contained an inert substance was made to Siesser’s home on Aug. 23 that year.

"Siesser believed the package contained the chemical weapon he had ordered, signed for the package and took it inside the residence," the Justice Department said.

Law enforcement officials later found the substance on a shelf in his garage, the department said.

They also found "two separate and seemingly unopened shipping boxes on the shelf next to it."

Inside those boxes were "approximately 10 grams of cadmium arsenide, a toxic compound, which can be deadly if ingested or inhaled; approximately 100 grams of cadmium metal; and approximately 500 mL of hydrochloric acid," the Justice Department said.

"An invoice for these products showed they had been ordered together on March 30, 2018."