Most crimes in the U.S. have a statute of limitations attached to them. That means that if a criminal is not captured and tried within a certain time frame after the crime has been discovered, then the state cannot charge an individual for that crime. While this may not make sense from a victim's standpoint, it allows for humans to self correct their behavior and the legal system to run more efficiently. But some crimes are viewed with such contempt by society that there is no limit on how long a person can be arrested for their crime.
A school teacher was arrested for allegedly sexually assaulting a number of women as far back as 2004. While there is no mention of why it took police so long to arrest the man on these charges, it is known that he stands accused by multiple women. The 40-year-old man allegedly assaulted a woman he met on the internet, as well as a fan of his band.