A Wisconsin man who killed three of his family members and another woman on Sunday may have been trying to copy the kidnapping of Jayme Closs, the teenager who this year escaped a captor who'd killed her parents, sheriff’s officials said.

Ritchie German Jr., 33, fatally shot his 66-year-old mother, Bridget, his 32-year-old brother, Douglas, and his brother’s 8-year-old son, Calvin, at their home in Lafayette, Chippewa County Sheriff Jim Kowalczyk said.

Chippewa County Sheriff James Kowalczyk addresses the media during a news conference on Tuesday in Wisconsin. (Dan Reiland/The Eau Claire Leader-Telegram via AP)

German then went to a home in neighboring Lake Hallie, where he killed 24-year-old Laile Vang with a shotgun and injured her parents before killing himself, the sheriff’s office said.

A couple of days before the attack, the suspect had sent Vang unsolicited sexual texts to which she responded: “Who is this? I don’t know you,” according to the sheriff’s office.

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.

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Authorities said German had handcuffs and a loaded handgun clip in his car, suggesting parallels with the Closs case. Closs was abducted from her parents' home on Oct. 15, 2018, in Barron.

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She eventually escaped her abductor, Jake Patterson, who was sentenced to life in prison in May for kidnapping the 13-year-old and killing her parents.

The Associated Press contributed to this report.