Twin in shooting-range pact wrote to Columbine survivor

They were smartly dressed - perhaps a little too smartly for an afternoon's target practice - but there was nothing about Kristin or Candice Hermeler that alerted anyone to the bizarre and tragic plan they had hatched.

Ninety minutes after renting two .22 calibre pistols at a Denver shooting range, the Australian identical twins were found slumped on the floor of their stall, each with a single bullet wound to the forehead. Kristin was dead; Candice, although seriously injured, was alive.

During a two-hour interview with police from her hospital bed, Candice confirmed that the 29-year-old sisters, from Victoria, had made a suicide pact.

But she refused to say why, leaving relatives and friends at a loss to understand why the pair - university-educated, well travelled and from a loving, middle-class family - had reached their decision.

A possible clue to their mental state was found by police, who discovered a photocopied magazine article about the April 20, 1999 Columbine High School massacre of 13 by Eric Harris and Dylan Klebold in luggage stowed in their Denver budget hotel.

Columbine school is a few kilometres away from the shooting range.

Denver TV station KCNC said Kristin wrote two letters in 1999 to Brooks Brown, a student at Columbine who in 1998 was bullied by Harris, but who later became friends with him. In one letter Kristin wrote, "As someone who has been rejected, victimised and ostracised in their life, I would like to thank you for giving him [Eric] that chance," the television report said.

She also thanked Brown for accepting Harris and fellow shooter Klebold who had been "rejected and victimised by so many others."

But Captain Louie Perea, of the Arapahoe County Sheriff's Office, said that the surviving sister told investigators that Columbine "happened a long time ago and she didn't care about it."

He said there was "nothing to indicate they were going to harm anyone other than themselves. There was never anything we came across to indicate that they had intended to do another Columbine".

The twins, who grew up in Bendigo and Melbourne, were in the US on 90-day cultural exchange visas, having arrived in August and September, three weeks apart. They had been in Colorado for about five weeks, and one of them - it is not clear which - was due to fly home on Tuesday last week.

On the Monday, they checked out of their hotel and took a taxi to the Family Shooting Centre 21km away. The pair had taken lessons there the previous week, and when they arrived, "their demeanour was jovial, chatty, back-and-forth", according to the range's owner, Doug Hamilton.

The women bought three boxes of ammunition and, between firing rounds at paper targets, joked and talked. Then, without warning, they turned their guns on themselves. Fellow shooters found Kristin lying on her back, while Candice was crouched on the floor with blood in her hair. The former died at the scene; the latter remains in a serious condition following brain surgery.

During the police interview, Candice was "devastated, frustrated, distraught and angry at times", Perea said.

As to why she and her sister decided to kill themselves, and in such circumstances, he told the Age: "We asked that on more than one occasion, and she declined to answer."

As the twins' South African-born parents, Ernest and Kelsay, flew to Colorado at the weekend, former friends and schoolteachers in Victoria described the women as quiet, cheerful and hard-working. Their cousin, Jacky Sole, who lives in Washington state, told News Ltd papers: "They grew up in a loving home. They didn't want for anything."

Both reportedly graduated from the Royal Melbourne Institute of Technology, and had made previous trips together to the US and Canada, working as nannies. Police said they did not plan to charge Candice, as she had shot only herself and had not assisted Kristin.

- additional reporting AFP