DENVER (AP) - An investigation into a suicide pact that left one Australian woman dead at a suburban Denver shooting range and her twin sister hospitalized with a head wound has been formally closed, Colorado investigators said Monday.
Arapahoe County Sheriff's Department investigators spoke to the surviving twin, Candice Hermeler, and her parents, who arrived in Denver on Friday, The Denver Post reported.
"We've made the determination there's not any more we can do on the case," sheriff's Capt. Louie Perea said.
Authorities said on Friday that they would not file charges.
Candice and Kristin Hermeler each fired a shot into their heads with rented .22-caliber pistols on Nov. 15. Kristin Hermeler died instantly. No suicide note was found.
Candice Hermeler told investigators about the suicide pact in a two-hour interview Thursday. But she refused to say why the 29-year-old sisters wanted to die.
Kristin Hermeler wrote two letters to a survivor of the 1999 Columbine school shootings just after the massacre, a Denver television station reported Saturday. She wrote that she was upset that bullying had apparently set off the two student shooters, adding that she and her sister had also been bullied in school.
The letters further suggested that the sisters had a fascination with the Columbine shootings, in which 15 people died.
The high school where the massacre took place is about 20 miles from the shooting range, and a photocopy of the Time magazine cover on Columbine was found among the twins' belongings after they shot themselves.
Candice Hermeler remained in serious condition at a Denver area hospital on Monday. The hospital hasn't commented on the type of treatment she has received and when she could be released.