An affirmative defense is essentially a legal justification for having committed a crime; that is, the defendant admits to having committed the crime, but raises a defense that if true would excuse him from criminal liability.  Once the defense raises sufficient evidence of an affirmative defense, it is up to the prosecution to disprove that affirmative defense, along with all of the charges, beyond a reasonable doubt.

Should

Previously, law enforcement needed to obtain a warrant prior to acquiring call location information.  A recently passed bill changes that, although only for emergency situations.

In order to thus obtain such information without a warrant, there must be probable cause to believe that an emergency situation exists such that an individual faces risk of death or serious bodily injury, and the time to request a warrant would increase that