The investigator “Rob Agnew” is a former FBI agent, and is almost certainly the same former FBI agent Robert Agnew who went along with USA Gymnastics officials covering up sex abuse by coaches of underage gymnasts:

That’s a really good piece. According to that article, it turns out the guy who made the request on behalf of the NFL was Robert Agnew. If this linkedin bit is right, he’s not an NFL employee, he runs his own firm and works on a contract basis for the Seahawks for security.