(a) In cases in which the victim reports an alleged sexual assault to law enforcement, the investigating law enforcement agency shall maintain any physical evidence collected as a result of an alleged sexual assault that contains biological material, including, but not limited to, stains, fluids, or hair samples that relate to the identity of the perpetrator of an alleged sexual assault, for 30 years from the date of arrest, or seven years from completion of sentence, whichever occurs last, and if no arrests, then for 50 years.

(b) If the victim chooses not to report the alleged sexual assault to law enforcement at the time of evidence collection, the law enforcement agency with jurisdiction shall maintain any physical evidence collected as a result of such alleged sexual assault that contains biological material, including, but not limited to, stains, fluids, or hair samples that relate to the identity of the perpetrator of the alleged sexual assault, for not less than 12 months from the date any such physical evidence is collected.