Collect as much identifying information at the scene or over the phone as possible, including:

• Complete Name (middle initial if you can get it)
• Address
• Cell/Home/Work Phone numbers
• Email Address/Facebook or Twitter ID
• Place of Work
• Relatives Names
• DOBs (not just age)
• License Plates/Car Models
• Web Sites
• Homeowner/Renter

Then go to:

LinkedIn
Nexis
PublicData
Pipl.com
Zabasearch
White Pages
HCAD
Texas Corporation Search
Facebook
Twitter and Search.Twitter.Com
Whostalkin.com