ARAPAHOE COUNTY, Colo. (CBS4) – CBS4 Investigator Rick Sallinger has learned why twin sisters from Australia may have come to Colorado to carry out their suicide pact.

Investigators found a magazine cover related to the Columbine tragedy at the La Quinta Inn where Kristin and Candace Hermeler, 29, were staying before they shot themselves. But their connection dates back to 1999, just a couple of months after the shooting.

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Kristin wrote two letters to Brooks Brown, a student at Columbine High School who was once targeted by Eric Harris, one of the Columbine gunmen.

Brown and Harris became friends before the April 20,1999 shootings at the high school.

In one letter dated June 12, 1999, Kristin wrote, “As someone who has been rejected, victimized and ostracized in their life, I would like to thank you for giving him (Eric) that chance.”

She went on to write, “Thank you for not judging and for accepting Eric and Dylan who were, from what I have heard, rejected and victimized by so many others. Thank you so much. Sincerely, Kristin.”

In another letter dated July 14, 1999, she wrote, “… you felt like everyone hates you. Words could never tell you how sorry I am that you feel like anyone hates you. It completely baffles me as to why anyone would hate someone when they don’t know them, it sickens me.”

Arapahoe County Sheriff’s Office said that Kristin died from a self-inflicted gunshot wound. Her sister, Candace survived after shooting herself. She remains in serious condition at Swedish Medical Center.

Her family released this statement Friday afternoon, “Our family would like to say thank you for the outpouring of support and concern shown during this past week. This is an extremely difficult time for our family. We would especially like to thank the Arapahoe County Sherriff’s office for their diligence and perseverance in determining the facts and circumstances of this situation. We are also grateful to the paramedics who responded and assisted our daughters.”

Ernest and Kelsay Hermeler also requested privacy.

The Hermeler twins were at the Family Shooting Center inside Cherry Creek State Park on Monday and were shooting for an hour and a half before the incident. The details of what exactly happened have been unclear until now because the surviving twin has been unable to communicate clearly to deputies what happened.

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On Thursday she was able to share the fact that the sisters had planned to commit suicide together and “did in fact shoot themselves,” according to authorities.

The sisters had been at the shooting range for lessons. Investigators believe they carefully planned out what was to be their final moments.

“In reality they walked in that gate right there just as jovial and smiling and talking to each other like a couple of gals out on a field trip,” said shooting range owner Doug Hamilton.

Because each woman turned the gun on herself, not the other, investigators said no crime was committed.

“Her demeanor was somewhat defensive which I believe any of us would. She is here in a foreign country being interviewed by law enforcement,” said Captain Louie Perea.

“But she was willing to speak with us and did speak with us for some length of time.”

The case has attracted international attention, bringing reporters from Australia to Colorado.

“In the beginning it has been a real mystery case, a puzzle that everyone has been quite intrigued in as the days have developed,” said Emma Dallimore an Australian TV reporter who recently arrived to cover the story. “It just seems more and more to be a very tragic story.”

“Based on the physical evidence collected, the surviving sister’s statements, and video surveillance footage from the shooting center the Arapahoe County Sheriff’s Office believes that this incident was indeed a suicide and attempted suicide,” the sheriff’s department wrote in a prepared statement.

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Officials said they are not releasing the video surveillance footage obtained from the shooting range.