Police have arrested a man they said tried to buy oxycodone at a New Canaan pharmacy using a fraudulent prescription.

David LaFrance, 33, of 121 Towne St., Stamford, was arrested Sept. 3 on charges of second-degree forgery, third-degree identity theft and attempt to obtain a controlled substance by fraud.

Police said LaFrance took a valid prescription he had previously received from a doctor, made a copy and changed some of the information, including the patient's name and the date. The suspect then went to Walgreens, 36 Pine St., New Canaan, on July 16 and attempted to buy Roxicodone, a brand of oxycodone, according to the report.

When the name on the prescription was entered in the computer, a note popped up stating that the man had attempted to pass a fraudulent prescription at a CVS Pharmacy in Westport the day before, police said. According to Sgt. Peter Condos, LaFrance also attempted to use the prescription in Weston and Faifield.

As the pharmacist picked up the phone to call the doctor and verify the information, the suspect became nervous and walked out without the forged document, according to the report.

During the investigation, police said they reached out to Soundview Medical Associates, 761 Main Ave., Norwalk, which helped identify LaFrance through a photo from Walgreen's surveillance video. The medical group's information also was on the prescription, according to police.

Condos said the suspect was very cooperative and claimed the had strong back pains and needed the painkillers. It is not clear whose identity he used on his forged prescription.

After learning a warrant had been issued for his arrest, LaFrance turned himself at 7 a.m. Sept. 3 and was transported to court the same morning.