A judge has declared Bill Cosby a “sexually violent predator” as a first step towards sentencing the 81-year-old comedian for drugging and sexually assaulting a woman over a decade ago.

The classification means Cosby must undergo monthly counselling for the rest of his life and report quarterly to authorities.

His name will appear on a sex-offender register sent to neighbours, schools and victims.

Montgomery County Judge Steven O’Neill made the decision as he prepared to sentence Cosby for violating Temple University women’s basketball administrator Andrea Constand at his suburban Philadelphia estate in 2004.

Bill Cosby arrives at  Montgomery County Courthouse
Bill Cosby arrives at Montgomery County Courthouse (Mark Makela/AP)

The comic once known as America’s Dad faces anywhere from probation to 10 years in prison after being convicted in April in the first celebrity trial of the #MeToo era.

Prosecutors asked for five to 10 years in prison. The defence requested house arrest, saying Cosby is too old and helpless to do time behind bars. He is legally blind.

Cosby’s lawyers had fought the “sexually violent predator” designation, arguing that Pennsylvania’s sex offender law remains unconstitutional and he is no threat to the public at his age.

But Judge O’Neill said prosecutors had met their burden of proof with “clear and convincing” evidence.

Ms Constand said in a statement submitted to the court and released on Tuesday that she has had to cope with years of anxiety and self-doubt that have left her “stuck in a holding pattern”.

Andrea Constand
Andrea Constand (David Maialetti/ Philadelphia Inquirer/AP)

The 45-year-old said her training as a professional basketball player had led her to think she could handle anything, but “life as I knew it” ended on the night Cosby knocked her out with pills and violated her.

She said she now lives alone with her two dogs and has trouble trusting people.

“When the sexual assault happened, I was a young woman brimming with confidence and looking forward to a future bright with possibilities,” she wrote in her five-page statement.

“Now, almost 15 years later, I’m a middle-aged woman who’s been stuck in a holding pattern for most of her adult life, unable to heal fully or to move forward.”

In the years since Ms Constand first went to authorities in 2005, more than 60 women have accused Cosby of sexual misconduct, though none of those claims have led to criminal charges.