The North Charleston police officer jailed last month was driving her patrol car to a store to buy alcohol when she crashed, according to an incident report.

The document, obtained Monday after The Post and Courier filed a Freedom of Information Act request with the S.C. Department of Public Safety, reveals new details about the April 22 arrest of 29-year-old Christina Mask.

Her marked North Charleston Police Department cruiser drifted off McMakin Street near Perry Drive in the Jedburg area and struck a culvert in a ditch about 1:05 a.m. She was off duty at the time.

An S.C. Highway Patrol trooper arrived about 1:30 a.m. and later noted in her report that Mask smelled of alcohol. A pint-size can of Smirnoff Ice Black rested near the disabled cruiser. Some of its contents had splashed in the front and back seats during the wreck.

The can was Mask’s, she told the trooper. Two empty cans inside the car also were hers, she said, according to the report.

She said she had downed two of the 16-ounce beverages and was working on the third when she wrecked, the report stated.

Mask added that she had been taking anti-depressant medications, had been having a hard time sleeping and had been awake since 5:30 a.m. the previous day.

She started drinking before midnight, but later left her Lake Drive home to buy the alcohol at a gas station. On her way back, she told the trooper, she fell asleep at the wheel and crashed.

The trooper’s findings were consistent with the officer’s story,

She walked about a half-mile home to get her cellphone and was returning to the crash site when Dorchester County Sheriff’s Office deputies found her, the report stated.

During a field-sobriety test, Mask performed well on some tasks, but her eyes didn’t smoothly follow the trooper’s moving pen, and she lost count while standing on one leg, according to the report.

A video from the trooper’s cruiser, which was released last week under the FOIA, showed Mask weeping as the trooper handcuffed her.

At the jail, Mask’s blood-alcohol level was later tested to be 0.17 percent, the report stated. She faces charges of driving under the influence and having an open container of alcohol in her car.

A North Charleston officer since 2009, Mask was placed on unpaid leave after her arrest.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.