The BOP will not post his incarceration location until he is transported there for security reasons. If he is being held in Leavenworth, there are three separate locations, one is county, one is private (CCA) and the other is federal. If you know the jurisdiction, the information is likely to be found by calling the Clerk of the US District Court and see if there is a sentencing date.
https://www.inmateaid.com/ask-the-inmate/hi-i-have-a-friend-that-is-awaiting-federal-sentencing-in-the-district-of-kansas-specifically-in-kansas-city-kansas-i-have-been-told-he-was-in-leavenworth-however-i-am-assuming-because-he-is-awaiting-sentencing-he-is-not-yet-in-the-bops-system-i-have-sear#answer
Accepted Answer Date Created: January 27,2015