Bill Cosby after his arraignment on Dec. 30 in Elkins Park, Pa. (Matt Rourke/Associated Press)

THE DECISION by prosecutors in Montgomery County, Pa., to bring 12-year-old sexual assault charges against Bill Cosby was greeted with elation by women who say they too were victimized by the comedian. “The best Christmas present they’ve ever received,” attorney Gloria Allred said of women she is representing in their civil claims against Mr. Cosby. That reaction is understandable, particularly since the allegations of sexual abuse were too long brushed aside. It’s hard, though, for us to feel anything but sadness — at the pain these women said they experienced and at the crumbling of an icon who was once revered for the good he did and for his ability to get us to laugh.

It was hard to see that man — the one who brought the world Cliff Huxtable and Fat Albert — in the frail 78-year-old who was arraigned Wednesday on three felony charges of aggravated indecent assault. Mr. Cosby is accused of drugging and sexually abusing a young woman he had mentored; the alleged incident took place at his suburban Philadelphia home on a January night in 2004. Attorneys for Mr. Cosby denied the charges. “Make no mistake, we intend to mount a vigorous defense against this unjustified charge and we expect that Mr. Cosby will be exonerated by a court of law,” they said in a statement.

The accused are presumed innocent, and it will be up to a jury to decide whether Mr. Cosby is guilty of these charges. It is hard, though, to accept claims of no wrongdoing by Mr. Cosby, given the sordid stories that have blotted his career. Andrea Constand, the alleged victim in the Pennsylvania case, is not alone in her accusations of abuse. More than 50 women have come forward with eerily similar — and credible — recollections. Mr. Cosby’s own words in a deposition in a civil suit brought by Ms. Constand damn him; he acknowledged securing drugs with the aim of giving them to young women he wanted to have sex with.

That deposition, which Mr. Cosby never thought would become public and which he fought to keep secret, apparently provided the additional evidence prosecutors said they needed to bring charges against him before the statute of limitations expired. Still, as legal experts point out, prosecutors face challenges with a case so old and one that previous prosecutors decided not to press.

Whatever the outcome of the legal case, another verdict — the one about Mr. Cosby’s legacy — has already been rendered: It is irretrievably gone. The inspiring messages embodied in his career — about the importance of family, self-reliance and understanding among the races — have been dirtied. Those who have been most hurt, including the women he allegedly abused, are the people who once looked up to him. For that, Mr. Cosby must bear the guilt.