Strickland

From Tardis Wiki, the free Doctor Who reference

Assistant Commissioner Strickland was the senior police officer who visited Jackie Tyler after she informed the authorities of the Doctor's presence. In fact, Strickland was Sip Fel-Fotch Passameer-Day Slitheen, a disguised member of the Family Slitheen, the real Strickland having been murdered previously. Revealing himself as a Slitheen, Strickland attacked Jackie and Mickey Smith in Mickey's flat. The Doctor, Rose Tyler and Harriet Jones assembled enough clues about the Slitheen's physical make-up for the Doctor to deduce their weakness - Jackie throws various kinds of vinegar over Sip Fel Fotch, causing him to burst, covering them with the remains of his body. (DW: Aliens of London / World War Three)