The gunman who shot dead three children and a rabbi at a Jewish school Monday was a cold, cruel killer who filmed his carnage, France's Interior Minister Claude Gueant said as the country prepared to hold a silent tribute to the victims on Tuesday.Gueant told reporters video surveillance tapes at the school in Toulouse showed the gunman was recording his shooting spree with a small video camera attached to his neck. "This adds another element to the profile of the killer. It is someone who is cruel enough to record it," Gueant said at a primary school in the southwestern city."This shows a profile of the murderer as someone who is very cold, very determined, with precise gestures, and therefore very cruel," Gueant added. French authorities on Tuesday expressed worry that additional attacks could follow. The killer who is believed to have murdered seven people over the last nine days remains at large. Authorities said forensic tests proved the person used the same .45 caliber pistol in all three shootings and added they were worried another shooting might be carried out. "We are concerned about the possibility that they want to commit a fourth attack," Gueant told Le Figaro.Schools throughout France observed a moment of silence on Tuesday at 11:00 a.m. local time in memory of the victims of the deadly shooting at the Ozar Hatorah school.Security at Jewish schools throughout the country remains tight while a large police presence was felt in in Toulouse, where two of the three killings ascribed to the spree killer took place. The third shooting took place in Montauban, a city 50 kilometers to the north.Eyewitnesses accounts have reported the suspect as being short and stocky. On two of the three shootings the person rode a black Model T-Max Yamaha motorcycle and wore a black helmet. One person said she saw he had a face tattoo. Le Point, a French weekly, reported on Monday that a group of former French soldiers discharged for having ties to neo-Nazi groups were suspects but the information could not be confirmed by French authorities. All the victims in the shootings were members of minority groups but police have so far not ascribed a motive to the the killer or released specific information on his or her identity.In Israel Tuesday, the National Insurance Institute said that all four French Jewish victims would be buried in Israel. The announcement came after NII's initial opposition to funding the burial of one of the victims, Rabbi Yonatan Sandler due to bureaucratic regulations regarding citizenship.Although Sandler was not an Israeli citizen, his wife and his two murdered children, were citizens. JPost.com staff contributed to this report.