After the recent tragedy in Florida, one question I’ve seen raised numerous times can be boiled down to this: why did the FBI and local police not act on any of the tips they’d received about the shooter?
The former allows a police officer to temporarily detain someone, and they must have a specific, articulate, demonstrable reason.
A common example is fitting the description of a suspect. Also if the police see you come out of an area known to be a drug hot-spot, they may detain you to ask you why you were through the area, as they have reason to suspect you were there to buy or sell drugs.
Probable cause is a higher standard. Basically it means the officer has evidence that you have broken some law. A traffic stop is an example of an officer having probable cause. But that is probable cause only to detain you.
To search your person or vehicle, the officer needs to be able to articulate 1. what he/she expects to find, 2. why he/she expects to find it, and, most importantly, 3. what evidence that gives the officer reason to believe they will find such.
These are your basic liberties against police intrusion in a heartbeat. All of us have them. Including those who would later become mass shooters.
Given this, it should be quite obvious why the police never acted on any prior tips regarding the Florida high school shooter: they likely could not even establish reasonable suspicion.
Any action of the officer must be demonstrable to the Court for it to stand up. If an officer said to a detained person they matched the description of a suspect, the officer needs to be able to articulate which suspect they resemble.
Reasonable suspicion isn’t “I heard so-and-so talk about wanting to shoot up the school”. That actually isn’t specific enough. It might be enough that the police may decide to question the individual, but without anything more, they cannot detain the person and most certainly cannot arrest them.
Tips have to be actionable, and if a tip doesn’t provide enough information to establish reasonable suspicion, the police won’t act on it beyond maybe asking questions. And without anything more specific, and without any actual, demonstrable evidence the person in question is up to no good, the police cannot do anything more.
To do anything more would be to violate the rights of the person they are investigating, which will sink any chance of any evidence seeing the light of day in Court. Even if that person is actually planning a mass homicide incident like what occurred in Florida.