Sometimes it’s surprising how many ways there are for an employer to get in trouble. You raised questions about outside screening, and about timing with the interview.
It may seem unjust that you can get in trouble for looking at someone’s public profiles, but the reality is that you don’t get in trouble for looking; you get in trouble for using information against the person in a discriminatory way. So to avoid that, you try to shield yourself from possibly using (or being accused of using) that information wrongly.
Whoever does the screening, you’ll need to have that conversation about how broadly they screen. This may depend on the importance of the position being filled, and whether the person even has an online presence. Some of my friends who are more old-fashioned (or more paranoid) barely have any online presence at all. If you use that third-party vendor, your attorney or a reputable vendor should be able to walk you through the Fair Credit Reporting Act criteria; that’s beyond the scope of this blog.
I guess what you’re asking is whether you screen people out in various ways before or after their employment interview. For all these background checks, medical tests, and so on, the weeding out should be after the interview, not before . . . we can talk about that more in an “interview” thread if you want.
Here’s another thing to address very early in a person’s employment (in their hiring packet). If you are an organization that likes to take photos or video, maybe to support your active presence in social media, simplify your life by getting written permission up front for you to use employees’ images, and have them assign the rights to use and publish the pictures or video to you. Then you won’t get in trouble for posting cute pictures.
Disclaimer: not official legal or psychological advice or opinion