Digital Forensics guidance on public information regarding criminal activity
Gangs use social media to broadcast everything from threats and brandishing weapons to admitting their involvement in murder. The Chicago Police Department seems very reluctant to use public information as probable cause to arrest or even reasonable suspicion to investigate crimes that are public information. I've read their policies provided to officers and their complete literature regarding First Amendment protected activity multiple times. There are short statements of a few sentences that declare public information on social media or YouTube does not require any special permissions, or policies to be followed for investigations as if the information were provided to them by a witness, victim or citizens with relevant information. This is within extensive rules and policies regarding everything from hand delivering official requests to notify multiple departments of a planned investigation and rules regarding equipment that can be used to the keeping of information they discover that could easily be interpreted as being required in any situation including when the information on criminal activity is open to the public.
I feel that their own policies don't give them a clear view of the difference between what is public and what requires extensive documentation and permissions so clear evidence of crimes is completely disregarded. In even several recent examples even here on Reddit (the murder of rapper Q50) the public has used information to quickly identify evidence leading to suspects who sometimes publicly claim responsibility or involvement in the murder. From the famous suspected serial killer King Von to his very famous partner Lil Durk who was recently acquitted on conspiracy to commit murder for hire charges who remains in custody facing a VICAR case involving another conspiracy to commit murder, public information showed their likely involvement for months or years before their arrests and prosecutions. Why does law enforcement disregard digital forensics of public information in order to rely on investigation procedures that existed before the advent of social media's existence?