Prosecutors preparing for Bill Cosby's sexual-assault trial hope to call 13 other accusers to try to show he drugged and molested women as part of a "signature" crime spree over five decades.

The defense will attack their credibility and try again to have the case thrown out at a pretrial hearing starting Tuesday in suburban Philadelphia.

The 79-year-old entertainer is charged over a single 2004 encounter with a former Temple University employee.

Pennsylvania law also allows testimony about "prior bad acts" if they fit a nearly identical crime pattern.

Prosecutors say Cosby routinely used his fame and power to befriend impressionable young women, then drugged and sexually assaulted them.

Cosby has pleaded not guilty and remains free on $1 million bail.