Amanda Knox: Murder on Trial in Italy

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The film depicts events that occurred after Amanda Knox moved to Perugia, Italy, in September 2007, as a foreign exchange student attending language classes at the University for Foreigners.
Knox shares a flat in a cottage with Meredith Kercher, a British student, and two Italian women, Filomena and Laura. In October, Knox meets Raffaele Sollecito, an Italian student of computer engineering, at a classical music concert, and they start dating.
On November 1, Kercher is found stabbed to death in her bedroom. Police question both Knox and Sollecito. Meanwhile, the chief prosecutor of Perugia, Giuliano Mignini, discusses the case with the coroner and forensic investigators from Rome. The coroner mentions that multiple bruises were found on Kercher's body, which could indicate a struggle between Kercher and her murderer. The prosecutor inquires whether more than one person could have been involved in the fatal attack.
During Sollecito's interrogation, he is informed by police that telephone records indicate he has called the emergency number after the Polizia Postale arrived on the day Kercher's body was discovered. He asserts that Knox told him to say that she was not with him at the time of the murder, and that he had not "thought about the contradictions" in his alibi.
Police ask Knox to explain a text message that has been found on her cell phone. The officers claim that Knox had left the message for her employer, pub owner Patrick Lumumba, on the night of the murder to tell him she would meet him later. Several hours later, Knox states that she had met Lumumba in a local square, that they had gone to the cottage with Kercher, and that Lumumba had entered Kercher's room before her death.
Knox, Sollecito and Lumumba are arrested. Under police interrogation, his face swollen with bruises, Lumumba insists he is innocent. Some days later, he is released when a university professor reveals that he had been with him at a pub, and could not have been at the cottage at the time of the murder. Knox's parents travel to Italy to help their daughter, and hire lawyers to defend her.
The forensics team finds a bloody fingerprint at the crime scene that does not match the prints of either Knox or Sollecito. The resulting manhunt leads to the arrest of Rudy Guede, originally from the CÃ´te d'Ivoire, whom Knox and Kercher had met weeks earlier. Guede later goes to trial and is found guilty of murder and sexual assault. Knox and Sollecito are indicted in the same court judgment.
Knox and Sollecito are tried jointly in 2009 on the charges of murder, sexual assault, staging a crime scene, and transporting a lethal knife. Luminol tests in the cottage hallway reveal footprints approximately the size of Knox's feet. DNA experts testify that Knox's blood was found on a bathroom tap, mixed with Kercher's. In Sollecito's apartment, police found a large kitchen knife with Knox's DNA on the handle. The prosecution insists that Knox had argued with Kercher and stabbed her, as presented in an hypothetical flashback set in Kercher's room.
The chief forensics investigator testifies that Sollecito's DNA was found on a metal clasp severed from the back strap of Kercher's bra (presented as being cut off with a knife in the flashback). Sollecito's attorney asks when the bra clasp was discovered. The investigator replies that it was photographed on the first day after the murder, but only collected 47 days later, during which time it had been moved from its original position and passed between the various members of the forensics team. Although the attorney claims that this small amount of DNA is possibly the result of contamination, the investigator replies that, with the exception of the clasp, only a cigarette butt in the kitchen held Sollecito's DNA, stating, "DNA does not fly around".
Eventually, in December 2009, the jury delivers a verdict of guilty: Knox is sentenced to 26 years in prison, Sollecito to 25 years. Knox's father reassures his daughter that he and her mother will appeal the verdict in a new trial. The film closes with a caption stating that the parents of the real-life Knox have both been charged with criminal slander for claiming that police had abused their daughter, and that they face three years' imprisonment if found guilty.
Note: The film is now shown with an amendment noting the subsequent acquittal of Knox and Sollecito on appeal.

Question: What other item held Sollecito's DNA?
Answer: Cigarette butt