ABC News December 31, 2015

Bill Cosby: A Legal Explanation of The Charge and What's Next

WATCH: Understanding the Charges Against Bill Cosby

After Bill Cosby was charged yesterday with aggravated indecent assault, the logical next question is what does this mean for the comedian in a legal sense.

The charge filed by the Montgomery County District Attorney's Office stems from a 2004 alleged incident between Cosby and his accuser Andrea Constand. Cosby settled out of court with Constand in 2006 during civil proceedings.

Read: Bill Cosby's Lawyer Monique Pressley Has 'Faith in Justice System' Related: Bill Cosby Arraigned for Alleged Aggravated Indecent Assault

"This is a game changer for Cosby ... If convicted, he'll almost certainly serve prison time," said Dan Abrams, chief legal analyst for ABC News. "But it's important to note that the burden of proof in a criminal case is higher. This is an old case and memories fade. They are going to have to prosecute and have to prove guilt beyond a reasonable doubt."

There are multiple factors why this case is being prosecuted now as opposed to 12 years ago, when the Montgomery County DA at the time chose not to press criminal charges. The most important difference seems to be Cosby’s deposition in Constand's civil case that U.S. District Judge Eduardo Robreno unsealed this past summer, where Cosby admitted to giving Quaaludes to a woman with whom he wanted to have sex.

"Also, all of the new accusers coming forward, which the prosecution will hope to call as witnesses," said Abrams. "And the fact that the statute of limitation was up in a couple of weeks."

The court should decide in advance what testimony and who will be allowed in Cosby's trial, Abrams said.

In 2005 Constand said the comedian invited her to his home in Pennsylvania the previous year and that on one occasion, gave her pills and wine, which made her impaired. That's when she claimed Cosby allegedly sexually assaulted her.

Speaking to "Good Morning America" earlier today, Cosby's attorney Monique Pressley said, "I expect now that all of those things will get ferreted out in a court of law and I have faith in the justice system."

Pressley said the decision not to charge Cosby in 2005 was the reason that "led my client into a civil process where he testified." She had previously called the charge "unjustified" and told ABC News, "We expect that Mr. Cosby will be exonerated by a court of law."

After his arraignment yesterday, Cosby was processed at the Cheltenham Police Department and released on $1 million bail. Cosby has not yet entered a plea and will next appear in court on Jan. 14.