Authorities: Couple tried to poison man's ex-girlfriends with cyanide, leading to hazmat responses

A 41-year-old woman prosecutors say was involved in a plot to poison two women in Middleton and Rock County was ordered held on $750,000 bond Wednesday as authorities continue to investigate a case that also implicates a man who briefly dated the two intended victims.

At the heart of the investigation into Andrea L. Whitaker and 43-year-old Paul Van Duyne Jr., both of Madison, has been a series of hazmat responses over the last three days at three Madison addresses that authorities believe might be contaminated with cyanide or other chemicals the couple used in an attempt to poison the women.

“It does appear that this defendant and Mr. Van Duyne have started dating and apparently created this plot to kill his ex-girlfriends by poisoning with cyanide, thallium and different poisons,” Dane County Deputy District Attorney William Brown said at Whitaker’s bond hearing Wednesday.

Brown said police were in the process of investigating the case when Van Duyne forced their hand by showing up at the alleged Rock County victim’s house in Janesville on Sunday, when he was arrested.

He is currently in the Dane County Jail, tentatively charged with attempted first-degree murder and stalking, while Whitaker is tentatively charged with harboring or aiding a felon.

According to Brown:

Van Duyne first came to the attention of law enforcement after a woman in Middleton reported that her car had been broken into twice while in the parking lot of the city’s Costco. After one of those break-ins, a water bottle that had been in the car, and from which the woman had taken a sip, was found to have been laced with cyanide. The woman was not injured, but police were able to tie the break-ins to Van Duyne.

They also believe Van Duyne was involved in a similar incident in Rock County, where a woman’s car was contaminated with cyanide and the woman had to be hospitalized for her exposure to the poison.

“The link between those two women (is) for a very brief period of time both of them dated this man, Paul Van Duyne,” Brown said.

After Van Duyne was arrested, one of the first phone calls he made was to Whitaker, telling her to take a computer and other items, believed to include poisons, out of a home he was using at 1401 Skyline Drive in Madison. Whitaker was arrested there late Monday morning by police who had the home staked out.

Messages between Whitaker and Van Duyne that were recovered by law enforcement were “extraordinarily concerning,” Brown said, and included “detailed discussion on different poisons, how to make them.”

“It’s believed that this defendant (Whitaker) has an academic background in pharmacology,” he said. “It’s likely she was the brains of the operation.”

As part of the investigation, several search warrants have been executed in Madison and have required the help of the state Department of Criminal Investigation, the National Guard, the FBI and other law enforcement agencies. Seven DCI agents have been hospitalized after being exposed to some of the chemicals or poisons that they’ve found in those searches.

Under conditions of her bail, Whitaker is barred from having contact with Van Duyne and the two victims in the case, as well as from parts or the entirety of seven streets in Madison where authorities are continuing their investigation: Fairway Drive, Dearholt Drive, Milward Drive, North Spooner Street, West Skyline Drive, the 5600 block of Schroeder Road and the 2300 block of Crossroads Drive.

Whitaker lives in an apartment in the 5600 block of Schroeder Road, according to the probable cause statement in her Monday arrest, and Van Duyne has been linked to a home at 122 N. Spooner.

In arguing for a lower bond, public defender Stan Woodard, who was acting as Whitaker’s attorney for the purpose of Wednesday’s hearing, pointed out that there is no criminal complaint against Whitaker yet and there’s no evidence that she knew what she was doing might be wrong.

“We have a lot of information here,” he said. “We just know that she knows this guy. He asked her do something and she did it.”

Brown said Van Duyne and Whitaker have done several things to slow the investigation down. Van Duyne had his car’s license plates changed, he said, while Whitaker was caught trying to conceal evidence.

Brown made clear on Wednesday that Whitaker is likely to face additional, more serious charges in the case. Brown said Van Duyne is expected to appear for a bail hearing on Friday.

Editor's note: This story was updated on June 20 to correct the name of one of the substances believed to have been used as poison in the alleged crimes.