Authorities looking for a missing northeast Iowa teenager with autism are moving the search in a new direction, starting Thursday (April 12, 2018).

Tony Thompson / Photo By: Elwin Huffman - Townsquare Media

Officials no longer plan to use volunteers in what's been a massive effort to find Jake Wilson, 16, of La Porte City. Over the last four days, more than 2,100 volunteers have searched about 255 square-miles of land in and around the community, checking and re-checking woods and farm fields with no signs of Wilson.

At a press briefing late Wednesday afternoon, La Porte City Police Chief Chris Brecher and Black Hawk County Sheriff Tony Thompson thanked the scores of volunteers who showed up to search for Wilson. They both emphasized that authorities don't have any plans to slow their search effort.

Chris Brecher / Photo By: Elwin Huffman - Townsquare Media

Moving forward, investigators now plan to utilize the help of specialists who are trained to search waterways and other spots that aren't easily accessible. The specialists will be focusing on areas of Wolf Creek and the Cedar River, and other hard-to-reach spots on land.

Thompson said there are currently about 30 local, state, and federal investigators actively working on the case.

Thursday marks the fifth day since Wilson disappeared. The autistic teenager has been missing since Saturday evening, when he went for a walk and didn't return home.