Kevin Ryan was introduced Sunday during a Blythewood, S.C., press conference by family members of Jake Ziegler, 18, and Ray Pierce, 17. Ziegler and Pierce were last seen when they left a party in Catawba County, S.C., after telling friends they planned to drive to Myrtle Beach, S.C., to observe the sunrise, then return home so Pierce could be at work the following afternoon, The Charlotte (N.C.) Observer reported Monday.
"We just need that next piece [of evidence] to give us another direction," said Ryan.
A search effort is focused on a 30-mile stretch of Interstate 77, where Ziegler last sent a text message Oct. 13, authorities said.
Ziegler's and Pierce's cellphones or debit cards have not been used since, police said, and officials with the Fairfield County (S.C.) Sheriff's Office said they think the pair may have been involved in a car wreck on the highway, concentrating the search from Rock Hill, S.C., to Columbia, S.C.