UPDATED 08/18/11 7:16 a.m.

NAPERVILLE, Ill. (CBS) – Naperville police aren’t saying it was a suicide attempt or threat, but an incident Wednesday had all the markings of it.

As WBBM Newsradio’s Bernie Tafoya reports, Naperville police were called around 3:15 p.m. to a wooded area near Hobson Road and Johnson Drive for a reported suicide in progress.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

In the parking lot for Goodrich Woods, they found a man slumped over the wheel of a parked car. The word “poison” had been painted vertically on two trees near the car, and on one of the car’s tires.

As a result, the DuPage County Bomb Squad was called to determine the safety of the vehicle. Several homes were evacuated as a precaution.

The motorist, a 49-year-old homeless man who most recently lived in Wheaton, initially attempted to drive away but was stopped by police and taken into protective custody, the release said. He was taken to Edward Hospital in Naperville for evaluation.

The vehicle was determined to be safe with no harmful materials inside, the release said.

Police closed Hobson Road between Johnson and Oleson drives during the investigation.

More than 30 people in the U.S. have committed or attempted suicide with chemicals in their cars over the past couple of years. They have also printed poison warnings on their vehicles.

Naperville police say no criminal charges have been filed against the man in this case, although they could be later if deemed appropriate.

The Sun-Times Media Wire contributed to this report.

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