A 37-year-old Elko man pleaded guilty on Friday to hiring two teen girls for sex as part of a deal that allegedly led to a liaison in an Eagan hotel room.

Charges say Mickey A. Cupkie, a former member of the Minnesota Army National Guard, used his smartphone while at work in St. Paul to look up the 15- and 17-year-old girls through the classified advertising website Backpage.com.

He then negotiated a money-for-sex deal via text message, authorities say.

One girl was a runaway being tracked by a Minneapolis police sergeant who suspected that she was being forced to prostitute herself. Using cellphone records and hotel surveillance videos, police later identified Cupkie as one of three males who went to the Eagan hotel on May 9 in response to the girls' ad, the charges say.

Two St. Paul men were charged later with pimping the two girls.

Ramsey County Attorney John Choi has cited the Cupkie case as an example of Backpage being used "as a platform to traffic minors for sex."

Cupkie will be sentenced on Nov. 1.