Welcome to the 21st Century! (Wow! We are already 15% into the 21st century!) When I first started practicing law in 1988, the resources available online were limited to lexis.com (which was and still is the leading legal research tool).
Now fast forward 27 years later and in a millisecond we can find out vital information about witnesses, including where they work, where they live, who they live with, what their hobbies and interests are, etc.
It is imperative that a trial attorney use the online tools to determine information about witnesses, especially adverse witnesses. You need to investigate whether the other sides witnesses have valid drivers licenses, have been arrested for a serious crime, or have otherwise committed an act which reflects on their credibility.
When a defendant’s expert witness (e.g., a physician who has examined your client) is about to testify, you need to inquire whether that witness has an active professional license. That information is easily accessible using government websites. You may find that a witness has been suspended or his license has been revoked due to malfeasance or a criminal act. This information can be used to impeach the testimony of that witness. Such impeachment often times results in a jury disbelieving the testimony of that witness.