This week, Bill Cosby was charged with three counts of aggravated indecent assault. The felony charges stemmed from an incident more than a decade ago, in which Andrea Constand says Mr. Cosby drugged and assaulted her in his home. Mr. Cosby says he intends to fight the charges, and no court has found him liable for sexual misconduct. The timing of the criminal charges was not arbitrary. The date of the alleged assault was Jan. 15, 2004, and Pennsylvania’s statute of limitations for rape and sexual assault is 12 years: If prosecutors had delayed two and a half weeks, the...