[Sherlock smiles just slightly when he sees that she's thought ahead.]

Careful. It's most likely not booby trapped, but we can't rule out the possibility after all of the precautions taken to keep this hidden.

[He slips his own set of lock picks out of his Belstaff. The case is older and more worn than Joan's, but that's simply because he's been had it a lot longer. It rarely got used back in London, but Americans don't seem to trust him as openly at the crime scenes for some reason.]