Police on Friday arrested a McHenry doctor accused of writing prescriptions for pain medications including oxycodone and fentanyl to patients who might not have needed them.

The McHenry County State’s Attorney’s Office contacted the U.S. Drug Enforcement Administration about 1½ years ago in relation to the “prescribing habits of physicians in McHenry County,” State’s Attorney Patrick Kenneally said.

The investigation came to a head Friday, when police arrested 67-year-old Thomas C. Tilot of McHenry on a $40,000 warrant.

Tilot, of the 6600 block of Burning Tree Circle, posted bail shortly after his arrest and was released from the jail at 9:33 a.m. Friday, records show. He has declined to comment on the allegations.

The doctor is charged in McHenry County court with delivery of a controlled substance. If the case were to go to trial and Tilot were to be found guilty, he could face between three and seven years in prison.

Tilot works out of an office at 5435 Bull Valley Road, McHenry. The office still is accepting patients, an employee confirmed Tuesday.

According to a five-count criminal complaint, Tilot unlawfully prescribed oxycodone, fentanyl and morphine to two patients between Aug. 4, 2016, and March 1. The investigation is ongoing, Kenneally said.

“This arrest should put everyone in the medical community on notice that the days of irresponsibly overprescribing narcotic drugs in this community are over,” Kenneally said Friday. “Prescriptions are supposed to help and heal, not kill people. ... We regard this as totally unacceptable and will be reviewing all future overdose deaths from prescriptions for any irregularities.”