Confronting a car theft

It is the 5th day after quitting OPNET and starting from the scratch again. Around 1pm today, I witnessed a theft who slide under my SUV trying to do something there. I quickly run out of the office while asking Jennifer to call 911. In the parking lot, I shouted at the guy "What are you doing there!!?" and enabled the distress alarm of the car. The guy quickly get out and shout some words at me and drove away quickly. It is a white small sedan.