However, Kowalczyk said investigators may never know why German carried out the attacks.

“What was the motive? Why did this happen? I don’t have the answer,” he said, asking anyone who had been in contact with German in the last week to call the sheriff’s office.

A couple of days before the attack, German sent unsolicited sexual texts to Laile Vang, but she apparently didn’t know him and replied “Who is this? I don’t know you,” authorities said. Kowalczyk said there is no evidence that the two had ever met.

Chief Deputy Chad Holum said authorities are going through about 10 cellphones and are working to find out how German got Vang’s phone number, but they suspect he may have gotten it off the internet.

Vang’s parents, 51-year-old Teng Vang and 39-year-old Mai Chang Vang, suffered defensive wounds and each had to have an arm amputated, authorities said. They remained hospitalized Tuesday but are expected to survive. None of the other four people, including three children, who managed to hide in the home during the attack, were hurt.