Someone theorized earlier (after news story of this warrant came out but before pdf was posted) that perhaps this particular warrant is more in connection with the attempted murder charge (shooting of the officer) than with Alanna's death. Possibly the fact that TH used a gun in the manner he did justifies the taking of the other weapons and related items.
bbm: If what I just posted above is true, then maybe this refers to articles of clothing that TH and the officer (instead of Alanna) were wearing at the time they both were shot -- maybe what was removed from them by the EMTs, etc., at the scene. (Even the handcuffs might have been left behind in the crisis, IMO.)
I'm also thinking the "blood swabs" may have been of blood deposits left at the house from the LE/TH wounds to determine "whose is whose" after the shooting scene. Maybe they are trying to determine/document exactly how the shooting of the officer and of TH went down, for legal reasons.