Does the fact that a young girl was detained in a poorly lit, high-crime area with gang activity justify a stop?

What is the test for determining whether a stop by the police is justified as an investigative stop? (California, United States of America)

What is the test for determining whether a person detained on suspicion of criminal activity has an objective manifestation that they may be involved in criminal activity? (California, United States of America)

Is a member of a street gang who actively participates in any criminal street gang with knowledge that its members engage in criminal gang activity liable for criminal activity? (California, United States of America)

What is the test for a police officer to stop and detain a suspect under suspicion of criminal activity? (California, United States of America)

When a police officer stopped a group of young men sitting on a stairway in a high crime area of a residential street, and found that they were smoking and depositing ash in the area, what is the effect of the stop? (California, United States of America)

When stopped by a police officer for failing to stop a pedestrian on a sidewalk, does the officer have jurisdiction to stop the pedestrian? (California, United States of America)

Can a driver who was stopped and questioned by police at the scene of an initial stop and questioning be removed and detained? (California, United States of America)

If a police officer stops a car and finds contraband in the vehicle and finds it to be illegal, what is the effect of the initial stop? (California, United States of America)

What is the test for a stop by a police officer in a motor vehicle stop? (California, United States of America)

Is a local police officer justified in detaining an endangered missing person? (California, United States of America)