The man who led police on a high-speed chase last week before crashing nearly head-on into another vehicle was fleeing from a jail sentence.

Glen Witham, 39, of Skowhegan failed to report to the Androscoggin County Jail after pleading guilty to felony theft, Somerset County District Attorney Evert Fowle said Monday.

Theft is a felony when it involves property valued at $1,000 or more. Witham’s plea was conditional, giving him the right to appeal a finding in the case, Fowle said.

When the courts denied his appeal, Witham was ordered to report to jail to begin a year-long sentence. He never showed up, Fowle said.

Witham remains hospitalized at Central Maine Medical Center in Lewiston. His condition has been upgraded from critical to serious, a hospital spokeswoman said Monday.

The driver of the other vehicle, 27-year-old Jenna Lawrence of Manchester, who is eight months pregnant, also was taken to Central Maine Medical Center. A family member said last week that Lawrence and her baby were expected to be all right.

The crash occurred around 1:30 p.m. Wednesday, while Witham was leading Androscoggin County sheriff’s deputies on a high-speed chase on Route 202 from Greene to Winthrop. Witnesses said his car veered over the center line as if he was passing, then hit Lawrence’s 2003 GMC Envoy near the Winthrop Veterinary Hospital.

Androscoggin County Sheriff Guy Desjardins said his department is doing an internal investigation, which is standard procedure whenever a deputy initiates a chase. Investigators will look at why deputies decided to chase Witham, and whether they followed county policy during the chase.