Anonymous Tips
This one is a little trickier, and I think the judge is wrong in his decision. Technically, the officer did not have RAS or PC to believe deberry was carrying a gun. Just an anonymous tip. Which, I believe has been ruled not RAS, someone please correct me if I am wrong. But due to the fact that deberry's actions raised the level of the stop to one which required the officer to act defensively, the officer then gained the RAS that he may be armed.
Anonymous tips are granted legal cause for RAS in circumstances where
1) The tip is made in a timely manner.
2) The tipper has identified themselves or has acted in a manner that easily lets them be identified. This includes times when people call into dispatch, knowing that it is a recorded and traced line. This, also, includes times when people approach officers on the street, allowing officers to identify them by their physical features.
3) The tipper indicates that they have direct knowledge of criminal activity or indicates that someone's actions MAY LEAD to criminal activity.
4) A tip is considered legal RAS when the threat to personal/public safety outweighs the "minimal invasion of a stop".
5) As seen in the People v. Lindsey case, even if the tipper did not actually see the crime, as long as the tipper has reasonable means to suspect a particular individual, the tip is cause for legal RAS.
So... to sum it up, Police CAN AND WILL use tips to use RAS as an excuse for stops.