Task: Question Answering
Input (English): Passage: Detective Aidan Breslin is a widower who has become emotionally distanced from his two sons, Alex and Sean. Due to his dental forensics expertise, Breslin is called to investigate a crime scene that includes human teeth and a painted message: "come and see". After matching the teeth to a missing man, Breslin investigates the murder of a woman, Mrs. Spitz, who was discovered hanging from a hook contraption in her bedroom; the same message appears on four walls. According to her autopsy report, she drowned in her own blood due to a precise stabbing. They also discover Mrs. Spitz had been pregnant, and the fetus was removed. Aidan speculates there were four attackers, who recorded the murder. After leaving the crime scene, Breslin comforts the Spitz's adopted daughter, Kristen.
The next murder shares the same M.O.; the similar hook contraption leads Breslin to a tattoo parlor whose owner constructed four devices. Another murder occurs, this time with no hooks and a message on three walls. While Breslin reviews the evidence at his home, Sean stumbles on one of the photographs. Sean's insights point Breslin to the Bible, where he discovers the killings are patterned after the Four Horsemen of the Apocalypse. Each room corresponds to a horseman; the "come and see" message is a quotation from the Book of Revelation. Kristen contacts Breslin unexpectedly, and, during their conversation, Kristen produces the missing fetus, confessing to the stunned Breslin. During her interrogation, Breslin discovers the darker side of Kristen's personality, one similar to the horseman War. 
Question: Who removed the fetus from Mrs. Spitz?
Output (English): Kristen.