Shocking rampage new reminder of gun violence just as families mark Sandy Hook.

Twelve kilometres away from Columbine and just before the first anniversary of the Newtown massacre where Adam Lanza shot 20 young children and six adults at Sandy Hook, a teenage gunman again opened fire in a suburban high school.

Yesterday police said the teenage Colorado gunman was armed with many rounds of ammunition, a machete and three Molotov cocktails for a planned commando-style attack.

In a shocking rampage that officials said lasted one minute and 20 seconds, the 18-year-old Arapahoe High School student identified as Karl Pierson fired point blank at fellow student Claire Davis before killing himself.

Davis, 17, was in hospital with severe head trauma. She was listed in critical condition and remained in a coma late on Sunday (local time).


But it could have been much worse, Arapahoe County Sheriff Grayson Robinson said yesterday. "The individual also had multiple rounds of shotgun ammunition strapped across his body, and he was also armed with a machete," he told reporters.

"It is our strong belief that [the gunman] came to this school with that weapon and multiple rounds, and his intention was to utilise those multiple rounds to cause harm to a large number of individuals."

Arapahoe High is 12km from Columbine High, the site in 1999 of a bloody incident involving two students that left 15 people dead, including the gunmen. The latest tragedy took place just a few kilometres from the sites of last year's Aurora cinema shooting that left 12 people dead and scores wounded during a Batman movie screening.

Pierson's original target was believed to be a librarian who coached the school's speech and debate team. The librarian, whose name was not released, had disciplined the teen in September for reasons that haven't been disclosed. The librarian was able to escape the school unharmed, Robinson said. The sheriff said Davis appeared to be a random target.

Pierson legally purchased his shotgun at a local store a week before the shooting and bought the ammunition the day of the shooting. Anyone 18 and older can buy a shotgun in Colorado; only those over 21 can buy a handgun.

After firing a round down a hallway, Pierson shot Davis who just happened to be sitting nearby with a friend as he headed toward the library.

Pierson fired another round down the hallway. He then entered the library, fired one shot and detonated one Molotov cocktail, which caused three bookshelves to catch fire. After that, he fired a fifth round, ran to a corner and shot himself.

Students and a teacher described Pierson as a smart and sometimes goofy student who often talked about his beliefs during class, sometimes even debating his teachers. They said he was outspoken about his Communist-leaning political views.

Frank Woronoff, a fellow student, told CNN: "He was the last person I would expect to shoot up a high school. He was honestly incredibly humble and down to earth. He was a little geeky, but in a charming way."

There was nothing to indicate a connection between the incident at Arapahoe High and the Newtown anniversary, the sheriff said.

John Hickenlooper, the Governor of Colorado, who was instrumental in toughening up the state's gun laws, lamented the "all-too-familiar sequence, where you have gunshots and parents racing to the school and unspeakable horror in a place of learning".

Church bells rang out across Connecticut yesterday, chiming 26 times, once for each victim of the Sandy Hook shooting.

The bells started to peel at 9.30am, the time at which Lanza shot his way into the elementary school. Each chime was interspersed with the reading of a victim's name.

In the White House, President Barack Obama and his wife Michelle lit 26 candles in honour of the 20 young children and six teaching staff shot dead a year earlier. The couple then paused for a moment's silence.

Families of the victims had lit candles in their homes to mark the anniversary of the last night they were to spend with their loved ones.

Relatives and the town authorities had urged the media to stay away from the community to allow them to mark the anniversary privately and there was no public memorial.

But Sandy Hook Promise, a group formed by parents of the victims to campaign for gun control and mental health care reform, expressed its shock at yet another such incident.

"We were horrified to hear today of a school shooting ... just one day before the one-year mark of the Sandy Hook shootings," said Tim Makris, the executive director. "It's time to start a new conversation to protect our children."

In his weekly radio and internet address, Obama said the nation has not done enough to make its communities safer by keeping dangerous people from obtaining guns and by healing troubled minds.

His efforts to pass stricter federal gun laws were defeated in the US Senate in the face of the implacable opposition of groups such as the National Rifle Association.

But in his address, the president praised the parents of Newtown, of which Sandy Hook is a part, for continuing that fight.

"Over the past year, their voices have sustained us. Newtown is a town like so many of our hometowns ... And on this anniversary of a day we will never forget, that's the example we should continue to follow. Because we haven't yet done enough."

In the absence of a public memorial, residents of Newtown launched a "Year of Service" in which they urged people to carry out "acts of kindness".

- Independent, AFP, AP