"No obvious reasons" why 3 siblings were killed by 15-year-old brother, Alaska State Troopers say

Authorities investigating the deaths of three children who were shot by their 15-year-old brother have not found any evidence that the shootings were planned, an Alaska State Troopers spokesperson said Thursday.

There also were "no obvious reasons for why he shot three siblings and took his own life," troopers spokesperson Tim DeSpain said.

"The only person - people - that know what really happened in that moment are deceased," he said. Investigators were confident that this was not an accident and confident that it was not planned, he said.