(CNN) Two days have passed since Jayme Closs' parents were found dead and the 13-year-old girl vanished. But as investigators scramble to find her, few answers have emerged.

More than 400 tips have poured in since Jayme disappeared from her Wisconsin home on Monday. But the FBI is pleading for more help in finding the girl, who is the subject of an Amber Alert.

#FBIMilwaukee needs your help, as the search continues to bring home 13 year old Jayme Closs, now missing & endangered after her parents were found dead in their home in Barron, WI early this week. Call the tip line 1-855-744-3879.#FindJayme pic.twitter.com/rNELlQKJb6 — FBI Milwaukee (@FBIMilwaukee) October 17, 2018

Investigators are trying to find out not only where Jayme is, but also what led to her parents' deaths in the small city of Barron. Closs' parents were fatally shot and their deaths have been ruled homicides, Barron County Sheriff Chris Fitzgerald said Wednesday. No gun was found at the scene, he said.

"I'll be honest. I'm struggling with this because I don't have some of those answers that I want to give you," Fitzgerald told reporters.

Relatives wait in agony

Read More