Italian prosecutors began their closing arguments Friday in the trial of an American student accused of killing her British roommate more than two years ago, according to AP. Prosecutors outlined the evidence they have presented in the trial against Amanda Knox and her Italian ex-boyfriend Raffaele Sollecito, according to AP. Knox and Sollecito are charged with murder and sexual violence in the 2007 killing of Meredith Kercher in the central Italian town of Perugia. They deny wrongdoing. Both have been jailed for more than two years and appeared to be tense as they sat in court Friday. Prosecutor Giuliano Mignini reconstructed what he says happened the night of Nov. 1, 2007, when the 21-year-old Kercher was slain in the apartment she shared with Knox. As he opened his remarks, Mignini focused on a key prosecution argument that Knox and Sollecito broke one of the apartment"s windows from the inside to stage a burglary. A stone was found in one of the bedrooms, and previous witnesses have said that shattered glass was found all over clothes lying on the floor, suggesting the glass was broken after the room was messed up. «The key to the mystery is in that room,» Mignini said, adding that it would be nearly impossible to climb that window and enter without hurting oneself and leaving blood traces on the shattered glass. Also, he argued, that window was the most exposed of the apartment, making it an unlikely choice for a burglar. Nothing in the room with the broken glass, which belonged to one of Knox"s and Kercher"s roommates, was reported missing, Mignini noted. Prosecutors were expected to formally make their sentencing requests to the eight-member jury Saturday, while a verdict is expected in early December. Knox and Sollecito could face Italy"s stiffest punishment, life imprisonment, if convicted of murder. A third man, Ivory Coast national Rudy Hermann Guede, was sentenced to 30 years in prison last year for Kercher"s murder in a fast-track trial he was granted at his request. He also denies wrongdoing and is appealing his conviction. Prosecutors say Kercher was killed during what began as a sex game. Defense lawyers for Knox and Sollecito are working on the theory that Guede was the sole attacker. The 22-year-old Knox maintains she spent the night of the murder at Sollecito"s house in Perugia. The 25-year-old Sollecito has said he was home working at his computer that night. He said he does not remember if Knox spent the whole night with him or just part of it.