Scenario 1: Suppose you learn that your neighbor's house was burglarized yesterday around noon. After thinking for a minute, you realize you saw a strange car in front of their house. You even wrote down the license # and a brief description of the car but did not call 911. First call 311 and report your information. Then post this information to the community as an alert. This creates an opportunity for others who may have seen (or will see) the car to add details about the car or the people in the car. The spirit of alerts is to not only warn people of imminent danger but also to give them something specific to look for.
Scenario 2: Suppose you witness a strange car parked in your neighbor's driveway. Also, suppose you don't know your neighbor very well or if you do, you don't know how to contact them to verify whether the strange car poses a threat. First, call 911 then submit an alert. This allows the neighbor who lives in the house to report whether he or she knows whats up (even if he or she is out of town). it also allows the community to monitor the neighborhood and provide more info. As more people participate, more information is gathered. This may include getting a license # or a photo of a suspicious person, if it is possible without putting yourself in harm's way.
Scenario 3: Suppose you witness a dirty looking man in a beat up van hanging out at a neighbor's house. You take the usual steps including posting an alert. Then, lo and behold, your neighbor who lives in the house in question calls you from work and tells you the suspicious character is actually his lawn service guy. And even though he looks shady, he is not a threat and in fact, he does good work. At this point, you can report this to everyone (law enforcement and community) so that no one bothers the man. You will know better next time the man does yard work.