Authorities searching the area around a rural Portland school for 7-year-old Kyron Horman said Wednesday that crews from all 36 counties in Oregon will join the search for the boy who disappeared Friday.
The Multnomah County sheriff's office has been leading the search since it began. The additional search-and-rescue teams were expected to begin arriving Wednesday night and would scour the area Thursday.
Kyron's family released a statement at a news conference asking residents around the school to check and recheck their property, outbuildings and sheds for any sign of the boy.
"Please don't stop," the statement ended, as read by sheriff's Capt. Mike Shults, who is acting as a liaison for the family during the search.
Shults said he has been with the family almost the entire time, and said, "I stand here in front of you today because I carry the burden of sadness and pain they're experiencing."
He said the family chose not to appear in order to keep the focus on Kyron rather than shift it to themselves.
The intensive search has included helicopters and dogs, and has stretched to metropolitan Portland as it entered its sixth day, but it remained focused primarily on a half-mile radius around Skyline Elementary School, which is atop a ridge with a mix of forest and open areas.
The search force, composed primarily of certified volunteers in neon-green vests and T-shirts, continued to check roadsides and venture into the dense foilage that surrounds the school.
Kyron disappeared Friday after a science fair at the school. He was last seen about 9 a.m., when his stepmother said she watched him walk down a hallway toward his second-grade classroom wearing a "CSI" T-shirt and dark cargo pants.
The search began after Kyron did not come home on the school bus after class and his stepmother called 911.
Multnomah County sheriff's Capt. Jason Gates said his agency was going to ask sheriff's offices statewide to call up several hundred trained searchers to assist the teams already in place, which includes the FBI.
Gates also said the FBI was installing a mobile command post to expand communications and computer resources.
He said investigators were still receiving tips "constantly" and tracking all of them down, but he declined to say how many tips have come in. On Monday, he put the number of tips at 1,200.
Gates said investigators had already checked with police in St. Helens after a 36-year-old man was arrested Wednesday following a report by a boy walking home from school Tuesday that the man tried to kidnap him.
Gates declined to give any other details. St. Helens police did not immediately return calls from The Associated Press on Wednesday afternoon.
Gates remained optimistic and said any decisions to scale back or stop the search will be made "when necessary," but the sheriff's office and other law enforcement agencies remain fully committed to finding Kyron.
He called the other counties' involvement "a natural progression" under a system to guide multiagency rescue operations that was approved by the Legislature in 2007.
The system was developed in the aftermath of a major search in December 2006 for a missing San Francisco family that got stuck in the snow on a remote mountain road in southern Oregon. James Kim died while trying to walk out to find help for his wife and two young daughters, who were rescued.