Setup system across from office entrance a month beforehand. Drop the tag into the target's coat at restaurant coat check. Trigger remote system based on proximity. Someone's probably already done this in a spy movie.
It'd be a much better idea to simply have a remote controlled system, using tech that's been around for decades. Though I suppose if you're truly paranoid, you might be worried about signals tracking. Maybe have it connected to the Internet and use thermite to wipe out the evidence after shooting.
It'd be a much better idea to simply have a remote controlled system, using tech that's been around for decades. Though I suppose if you're truly paranoid, you might be worried about signals tracking. Maybe have it connected to the Internet and use thermite to wipe out the evidence after shooting.