Nothing seemed unusual with Lt. Hans Walters on Saturday night.
"He didn't seem out of the ordinary at all," said one Las Vegas police officer, who asked to be anonymous. "Cops are pretty intuitive. They can tell when something's wrong with someone.
"He seemed totally fine."
But two days later, something clearly changed.
Authorities said Walters killed his family, set his Boulder City home ablaze and then killed himself Monday morning.