Students returned to classes at Arapahoe High School on Tuesday.
LITTLETON, Colo. - The parents of the student gunman who shot a 17-year-old girl at Arapahoe High School on Friday released a statement saying that they are shattered and devastated by last week's events.
Karl Pierson's parents, Barbara and Mark Pierson, released this statement Monday afternoon:
"We are shattered by the tragic events that took place on Friday at Arapahoe High School. Our thoughts and prayers are with Claire Davis and her family. They, and she, have suffered unimaginably, and we pray for her full recovery. We also pray for the entire Arapahoe High School community, as we know your lives are forever changed by this horrific event. As parents, we loved our son Karl dearly and we are devastated by what happened Friday. We cannot begin to understand why Karl did what he did. We ask for privacy during this unthinkably difficult time and hope that you will respect our need for time to grieve."
Karl Pierson died from a gunshot wound to the head, the coroner's office confirmed Monday.
The Arapahoe County Coroner's Office performed an autopsy on Karl Pierson and classified his death as a suicide.
Pierson, 18, went into the school armed with a shotgun, a sling of ammunition, a machete and three Molotov cocktails, looking for the school's librarian, Tracy Murphy.
Murphy was head of the school's speech and debate team and had recently disciplined Pierson.
Murphy learned quickly Friday afternoon that Pierson was looking for him and left the building, a move that the sheriff praised as a "very wise tactical decision."
Murphy was not hurt.
Pierson shot senior Claire Davis in the head at point-blank range on his way to the library, Arapahoe County Sheriff Grayson Robinson said.
As of Monday, Claire was in a coma in critical but stable condition.
Claire was "simply in the wrong place at the time," Robinson said. There is no indication that the gunman knew her other than that they were both seniors at the school.
Coverage: Arapahoe High School Shooting
Teachers and staff went back to work at Arapahoe High School on Monday. Students will return to classes on Tuesday.
An online petition drive is asking Littleton Public Schools to give Arapahoe High School shooting victim Claire Davis a diploma at graduation in May.
When an armed student went into Arapahoe High School on December 13, many people sprung into action.
Claire Davis' father asked people to forgive the fellow student who shot and killed his 17-year-old daughter at Arapahoe High School.
The Arapahoe High School shooter entered the school through a door that should have been closed and locked, but was left ajar, Arapahoe County Sheriff Grayson Robinson said.
Gov. John Hickenlooper orders flags lowered to half-staff Wednesday in honor of Claire Davis, the student slain in the Arapahoe High School shooting.
Tickets to the celebration of Claire Davis' life are now available for students and staff at Arapahoe High School.
Claire Davis will be celebrated next week with a memorial at the National Western Stock Show and Complex.
Prosecutors are warning people that scam artists may try to take advantage of the shooting death of Claire Davis at Arapahoe High School by setting up phony websites and requesting donations.