Gunman in Colo. high school shooting shot self when confronted by officer

 The 18-year-old Colorado man who shot a fellow student before killing himself Friday intended to shoot numerous people, but his rampage was interrupted by a school resource officer who responded to the shooting, officials said Saturday. Ed Andrieski / APArapahoe County Sheriff Grayson Robinson holds a picture of Claire Davis the 17-year-old student that was shot during a briefing Saturday, Dec. 14, 2013, at Arapahoe High School in Centennial, Colo. Davis was shot by 18-year-old shooting suspect Karl Halverson Pierson at the school on Friday before he took his own life. “His intent was evil,” Arapahoe County Sheriff Grayson Robinson said of Karl Halverson Pierson. “And his evil intent was to harm multiple individuals.”Upon entering the school, Robinson said, Pierson fired one round down the hallway. He then shot Claire Esther Davis, 17, who just happened to be sitting nearby with a friend as he headed toward the library. The girl suffered severe head trauma and remains in critical condition at Littleton Adventist Hospital.Confronted by the officer, the teen committed suicide less than a minute and a half after he entered the building, armed with a shotgun and multiple rounds of ammunition that he purchased legally, the sheriff said.In a statement, Claire’s family asked for “continued prayers” for the teenager, who remained in critical condition.“She was an innocent victim of an evil act of violence,” Robinson said.He then read the statement from her family:"Our beautiful daughter Claire Davis has severe head trauma as a result of a gunshot. She needs your continued prayers," the family said.Authorities release the name of the shooting victim and offer a timeline of the incident, which took just one minute and 20 seconds. NBC's Ron Mott reports. They also expressed their gratitude to first responders and the trauma team that responded during Friday's brief incident at Arapahoe High School in Centennial, Colo.,  “for saving our daughter’s life and quickly getting her into surgery,” according to the statement.Robinson said he does not believe Davis and the shooter knew each other.  Davis had been previously identified as a 15-year-old student. Robinson said the student gunman purchased the pump-action shotgun used in the shooting incident legally on Dec. 6 at a local retail outlet, then legally purchased multiple rounds of shotgun ammunition on Friday morning. Pierson was also armed with a machete and three Molotov cocktails, one of which was set off. Robinson said the explosives were made of 12 to 16 ounce bottles containing flammable liquid and were brought into the school in a backpack. The weapons were found on and around the shooter's body, he said. Pierson set off one of the Molotov cocktails, setting a fire in the library. Robinson said the response of a school resource officer was “absolutely critical” to the fact that that there were no additional injuries or deaths.The parents of a 17-year-old student shot and critically wounded in a Colorado school shooting said "she needs your continued prayers" in a statement read by Arapahoe County Sheriff Grayson Robinson Robinson said Pierson entered the school from the north side and fired one random shot down the hallway before firing at the victim at point blank range.Pierson then entered the library and ignited one of the Molotov cocktails.The deputy sheriff then ran through a long hallway from the cafeteria to the library. While the deputy was containing the shooter, the shooter took his own life at the north end of the library, Robinson said.Robinson said the motive in the shooting was seen "as some type of retaliation" against a school staff member. Robinson said that Pierson was subject to disciplinary action from the school's debate team coach in September, but denied reports that he had been kicked off the debate team.  The Associated Press contributed to this report.