Police have upgraded charges against a 19-year-old man in the death of a York region officer, whose funeral is expected to draw thousands of mourners Wednesday.

A manslaughter charge against Nadeem Jiwa was upgraded to first-degree murder Tuesday.

He was out on bail when 43-year-old Const. Rob Plunkett was killed in the line of duty.

Thousands of police officers from both Canada and the U.S. are expected to attend the funeral service, along with Ontario Lt.-Gov. James Bartleman.

The 22-year-veteran officer died last week while investigating air-bag thefts. He was trying to make an arrest when he was hit by a vehicle.

Jiwa was with another man at the time of the incident.

Baseer Yousafzai, 23, is charged with breach of recognizance, theft and possession of stolen property, and mischief to property.

Plunkett was dragged by a car, pinned to a tree and thrown onto a residential street in Markham, just north of Toronto. He died a short time later in hospital.

Plunkett, a husband and father of three teenagers, was described by Chief Armand LaBarge and colleagues as a "true hero."

Plunkett earned a bravery award in 1998 for rescuing a senior from a frozen lake and worked with the Special Olympics for more than 20 years.

He is York's first officer to die in the line of duty since 1984, and just the third in its history.

He will be laid to rest at a full police funeral Wednesday. The service will begin at 11 a.m. at the Ray Twinney Recreation Complex in Newmarket.

A funeral procession will then proceed along Yonge St., passing honour guards of officers from Toronto, Durham and Peel.

Members of the RCMP, Ontario provincial police, Canadian Forces, and emergency and firefighting services will also pay their respects.