State and Suffolk County police say FBI aerial photos prompted them to return to the island's south shore.
Investigators would not say whether the images provide more evidence.
Police fanned out east of the previous search areas, where they have found the remains of 10 people since December.
Police believe a serial killer may be responsible for the deaths of at least four prostitutes whose bodies were found in the area. Authorities suspect other killers may have also left victims along the remote parkway, going back at least a decade.