Ancient History / Mythology:
Now dear, remember, if you feel scared, you can always trust a police officer. Police officers are your friends, and would never do anything to hurt you.
Modern Times / Reality:
Now dear, if you see the police, be very careful and don't draw any attention to yourself. Get away as quickly and quietly as you can. Also, snitches get stitches, so keep your mouth shut.
*** Your mileage may vary depending on ethnicity, socioeconomic status, clothing and a variety of secret factors outside of your control. *