The 29-year-old women, Kristin and Candice Hermeler, shot themselves early last week. Kristin Hermeler was killed and Candice Hermeler is still in the hospital with injuries to her head.
The Arapahoe County Sheriff's Office says no charges will be filed in the case, but deputies still do not know why the women wanted to kill themselves.
Tuesday, the sheriff's department released surveillance video from the shooting range in Cherry Creek State Park where it happened. Because of the angle of the camera, it does not show the actual firing of the weapons. Witnesses say the women appeared to be happy before the shooting.
According to newly released documents, when investigators went through the women's belongings at their hotel, they found several self-help and spiritual books. There were also some articles and clippings about the 1999 Columbine shootings, and correspondence from the family of Columbine gunman Dylan Klebold. There was also correspondence with the family of Columbine victim Cory Depooter.
Investigators say they also found a copy of the Time magazine cover on the Columbine shootings in the women's belongings.
It was already know that in 1999, Kristin Hermeler wrote letters to Columbine survivor Brooks Brown.
When investigators interviewed the surviving sister, Candice Hermeler, she told them she did not care about the Columbine attack and that it happened a long time ago. She refused to say why she and her sister wanted to die.
(KUSA-TV © 2010 Multimedia Holdings Corporation)