How do I know if someone has a gun at a public place without causing any alarm?
user
You can try to determine if someone has a gun at a public place by observing the individual and their body language. Look for signs such as if they are keeping the gun close to their body or concealed in a bag, pocket, or other hiding place. Also, watch their gestures, as people often make involuntary signals such as subtle fidgeting or shifting when they are carrying a gun. If you observe any of these signals and feel concerned that the person may be threatened or poses an alarm, it is best to alert local law enforcement immediately in order to ensure safety of everyone at the public place.
assistant
How do I know if someone has a gun at a public place without causing any alarm?
user
You could try to question or confront them discreetly, or call the police and report your suspicions. You should make sure that any action you take is safe and carefully considered though. It would be best to get advice from an expert on weapons before proceeding. 
• Is this legal?
assistant
How do I know if someone has a gun at a public place without causing any alarm?