A judge overseeing the sexual assault trial against Bill Cosby will allow the prosecution to have an additional accuser testify.

The Montgomery County prosecutor had asked to present 13 witnesses, drawn from dozens of women who say the legendary entertainer assaulted them, but the judge is only allowing one. From Philly.com:

In a one-page order, Judge Steven T. O’Neill offered little explanation for his decision to bar prosecutors from calling 12 other women they hoped would establish a decades-long pattern of sexual misconduct by Cosby. It was not clear whether a full opinion would be coming later in the day. The judge’s ruling effectively narrows the scope of the trial, which could begin later this spring.

However, the NY Times reports, "Legal experts have said that the account of another woman describing what she said was an act of sexual assault will strengthen the case against Mr. Cosby, 79, who has denied any misconduct."

The sexual assault at the center of the trial is a 2004 incident where Cosby is accused of drugging and raping Andrea Constand at his Elkins Park, Pennsylvania mansion. Cosby long maintained that his relationship with Constand, a basketball manager at Temple University, Cosby's alma mater, was consensual, but a deposition released in 2015 revealed that Cosby admitted to procuring Qualuudes to give to young women.

After Constand filed her complaint in 2005, prosecutors investigated but eventually dropped the case due to lack of evidence. Cosby also settled with Constand in the midst of the deposition. However, after more and more women stepped forward to describe Cosby as a predator, prosecutors reopened the case and arrested Cosby for rape in December 2015.

The Times has interesting context about why an additional accuser is being able to testify:

Ordinarily, prosecutors cannot introduce evidence or accusations of prior bad behavior. Such inclusion is typically viewed as too prejudicial for a jury as it considers the facts of the single case before it.

But in Pennsylvania, as in other states, evidence of so-called prior bad acts is permitted when it shows conduct so similar it can be argued that it demonstrates a common scheme or plan, a kind of unique signature of the defendant. For sex crimes, this can be important, experts say, because the defense in these cases often revolves around mistaken identity or consent, and the problems of proof are substantial. Having multiple accusers say they were victims of the same crime by the same person goes directly to these issues of identity and consent, experts said.

Cosby's team is trying to get the trial moved to another venue, with a motion stating, "It is difficult to conceive of a case in recent history that has generated more widespread, inflammatory and sustained media coverage than the current case against Mr. Cosby. Branded variously a monster, sociopath, and sexual predator, everyone from the current District Attorney of Montgomery County to President Obama has publicly weighed in on the allegations against Mr. Cosby."