CNN.com: Elderly man drives with body in windshield

ST. PETERSBURG, Florida (AP) -- A 93-year-old driver apparently suffering from dementia fatally struck a pedestrian and drove for three miles with the man's body through his windshield, police said.

Ralph Parker was stopped after he drove through a tollbooth on the Sunshine Skyway, Traffic Homicide Investigator Michael Jockers said. The toll taker called police, he said.

Parker was not likely to face charges because he did not appear to know what happened or where he was, said Bruce Bartlett, chief assistant in the Pinellas-Pasco County State Attorney's Office.

When should driving privileges be revoked? For a demented person, who has lost so much already, this can be "the final straw" - the crisis that can lead to violent and/or suicidal behavior. I've been threatened by patients who did not want to hear my opinion of their driving abilities. Here's an article from the Alzheimer's Association:

The Driving Dilemma
When Should a Person with Alzheimer's Relinquish the Keys?

"Behind the wheel, the person with Alzheimer’s may forget directions and landmarks and become lost, disoriented, and— worse yet—a danger to himself and others. With grandchildren in the car’s backseat and wife beside him, R. Swisher, who has Alzheimer’s, accelerated into the street, narrowly avoiding being hit broadside by two other cars going 40 miles per hour. Another time, he changes lanes into a car’s path.

"Despite his wife’s insistence that her husband not drive, her fervent please were ignored. She writes: 'Our primary care physician wrote a ‘Do Not Drive’ prescription. He refuses to go back to that doctor.'

"Readers who shared their experiences for this 'Dialogue' column said the decision to sell the car or hide the car keys was painful. "This was the first big life change for Mom as a result of Alzheimer’s. It made the disease real to us—the point of no return," writes Jane Gaboury, of Alpharetta, Georgia, whose 71 year old mother Cecile regularly drove through stop signs before ceasing to drive.

"'The questions of whether or not driving restrictions should be enforced for people with Alzheimer’s is simple in theory and difficult in reality,' notes Gaboury. "In theory, people who are impaired must not be allowed to drive, whether that impairment is the temporary result of alcohol or of a more permanent condition such as Alzheimer’s." Yet caregivers question how family members can determine when the impairment is sufficient to warrant driving restrictions..."