Elizabeth McKeown (Greene County Jail photo)

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A defendant charged with murdering a Springfield woman, a stranger, by allegedly running her over in November 2018 might argue at her upcoming trial that her ability to know right from wrong was diminished by her use of cough syrup.

According to online court records, Elizabeth McKeown, who is 49 or 50 years old, while in custody after the death of Barbara Foster, was to be tested to “determine liver function and the ability to metabolize dextromethorphan,” which is used in cough syrups.

Jon Van Arkel, McKeown's lawyer, did not respond for comment for this story.


McKeown changed her plea in 2019 from the standard not guilty to not guilty by reason of mental disease or defect.

Court records indicate McKeown was to be tested for her body's ability to metabolize dextromethorphan in 2021.

The test, if performed, could possibly indicate whether the drug could have built up in her system prior to the death of Foster.

In looking at the case, I was unable to see about a dozen online motions and filings because they were marked “secured” on Case.net, the online database for Missouri courts.

This case is hard to forget because of McKeown's apparent heartless reaction to the death.

McKeown allegedly told police she got upset sitting in afternoon rush-hour traffic behind Foster's vehicle on Nov. 20, 2018 — on Campbell Avenue near University Street — because she was in a hurry to get to the bank to make a car payment.

A probable cause statement says McKeown told police that when Foster “wouldn't go,” she started nudging Foster's car and then “decided to hit it full out.”

After the impact, the statement says, Foster got out of her car to assess the damage, and McKeown hit Foster with her Ford Mustang.

The probable cause statement says:

“McKeown stated, ‘the lady with the glasses' (Foster) was yelling at her. McKeown then said, ‘I tricked her, you know make her think I was going to be nice, be still and everything.'

“McKeown stated Foster started looking at the damage to her vehicle and McKeown ‘backed it up and then I slammed into her and cut her in half.' McKeown said she just wanted to pay her car payment.”

Foster, the victim, worked at Eyeglass World.

Seattle doc, convicted of murder, had mentioned cough syrup

A “cough-medicine defense” would be unusual. At least that's my conclusion in doing quick research.

Emily Shook, a Greene County prosecutor in the case, said she does not know how common such a defense would be.

I found a case in Seattle in which a physician used a knife to kill his partner and their 2-year-old son in 2011. His attorney initially argued the physician was affected by cough medicine and his body's inability to metabolize it.

But the physician pleaded guilty and was sentenced to 49 years.

According to a story in the Seattle Times, Dr. Louis Chen's attorneys said the “physician suffered from longstanding mental illness that culminated in a psychotic break inflamed by self-medication and a buildup of a drug found in cough syrup.”

A prior story in the Seattle Times quoted Mary Fan, a University of Washington law professor.

“I’ve definitely heard of induced psychosis through taking various drugs,” but never a criminal case involving cough syrup, she said, adding that cough syrup can produce the equivalent of a high, and like any drug that’s abused it can lead to intoxication.

According to the National Library of Medicine:

Dextromethorphan might cause side effects, including: dizziness, lightheadedness, drowsiness, nervousness, restlessness, nausea, vomiting and stomach pain.

Symptoms of overdose might include: hallucinations, nausea, vomiting, drowsiness, dizziness, unsteadiness, changes in vision, difficulty breathing, fast heartbeat, seizures and coma.

This is Pokin Around column No. 31.

Steve Pokin

Steve Pokin writes the Pokin Around and The Answer Man columns for the Hauxeda. He also writes about criminal justice issues. He can be reached at spokin@hauxeda.com. His office line is 417-837-3661. More by Steve Pokin