In attempting to locate a witness, what sources might you consult?

Sources that could be consulted in attempting to locate a witness include a telephone directory, a city directory (available in the library or on the web), and online people finders.
Other sources of information include:
• Media reports, for example, newspaper articles and television videos covering the event being investigated
• Court records, such as probate proceedings, lawsuits, and the like
• Deeds to property, usually located in the county courthouse
• Birth, marriage, and death certificates
• Voter-registration lists
• The post office, at which the witness may have left a forwarding address
• Credit bureaus
• The tax assessor's office
• City utilities, such as the local electric or water company
Professional organizations may be useful sources as well, if you learn the witness's profession.
You might also check with federal, state, or local governmental agencies or bureaus to see if they have information contained in public records that would be helpful in locating the witness.