This is the big legal question at the heart of the sexual assault case against Bill Cosby
The answer to one question could have a big impact on the outcome of the case accusing Cosby of drugging and sexually assaulting a former Temple University employee named Andrea Constand in 2004: Will his other accusers be allowed to testify?
In many other alleged assaults from decades ago, Cosby can't be charged because the statutes of limitations have passed. However, the law may allow his other accusers to testify in the Constand case - if prosecutors can show their testimony would demonstrate a "modus operandi" or a "common scheme," according to defense attorney Stuart Slotnick.
"There is legal precedent that allows the prosecution to bring in instances of prior bad acts or uncharged crimes to demonstrate that the defendant acted in a similar kind of way," said Slotnick, a partner at Buchanan Ingersoll & Rooney.
"There will no doubt be a huge fight between both sides, the prosecution seeking to admit as much of this evidence as possible and the defendant trying to preclude it as overly prejudicial," he added.
The accusations against Cosby have common threads that paint a picture of a man who allegedly used his power and influence in the entertainment industry to seek out vulnerable young women and lure them in with the promise of mentorship.
Some accusers have said they felt discouraged from going public because of Cosby's fame, power, and reputation as "America's dad." Moreover, virtually all of their accusers said Cosby drugged them.
"In all, or almost all, of the cases involving Bill Cosby, the alleged victims describe Cosby giving her a pill that renders her unconscious and awakens to find that she's been assaulted," Wesley Oliver, the criminal justice program director at Duquesne University, told NBC News. "And there are a lot of women who describe this occurrence."
"This is as close to a signature sexual-assault crime as it gets," he added.
Gloria Allred, a famed lawyer who represents 29 of Cosby's accusers, has said they are "prepared to testify."
For their part, Cosby's lawyers have blamed the prosecution against him on local politics.
"The charge by the Montgomery County District Attorney's office came as no surprise, filed 12 years after the alleged incident and coming on the heels of a hotly contested election for this county's DA during which this case was made the focal point," Cosby's attorneys said in a Wednesday afternoon statement posted by the Washington Post.
"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."