We are not asking you to put your life on the line. So don't intervene if you see a crime in progress; CALL 911!...and take good notes. Here is some helpful information you can provide, when talking to the 911 operator or responding officer.
PHYSICAL DESCRIPTION: Hair color and length, height, build (use comparisons if need be; for example: about size of responding officer, or yourself, even a well-known public official or actor), gender, facial hair...etc.
DRUG/ALCOHOL USE: Has the person been doing drugs, or consuming alcohol.
WEAPONS: Has there been mention of weapons, or have you observed a weapon. Are there weapons in the home; if taken place i a residence.
CLOTHING DESCRIPTION: Hat, coat, shirt, pants, footwear.
VEHICLE: Color, make and model, 2-door or 4-door, rusty, dents, stickers, tinted windows, direction of travel, plate number if possible.
If someone you know is involved:
NAME: Full name if known; include any nicknames or aliases.
ADDRESS: Number and street; also provide any location he/she is known to frequent.
CURRENT LOCATION: Especially important if apprehension should be immediate, such as in domestic assaults and A&B.
CONTACT INFORMATION: Land line phone, cell phone.
Again, DO NOT! risk your safety. Although the apprehension of criminal suspects is important, it's not worth your safety.