Search intensifies for 11-year-old Colorado boy Gannon Stauch missing for more than a week

COLORADO SPRINGS, COLO. -- The search has intensified for an 11-year-old boy in Colorado who has been missing for more than a week.

The FBI is assisting multiple agencies and volunteers in searching for Gannon Stauch.

"I'm begging, I'm pleading, if anybody has any type of lead, put yourself in my situation," his mother, Landen Hiott, said.

She begged everyone to stay vigilant, as Gannon requires special medication.

His stepmother, Letecia "Tecia" Stauch, was the last one to see him on Jan. 27. She said Gannon Stauch left to walk to a friend's house.

However, neighbor Rockerick Drayton said he searched through his home surveillance video as the search intensified. Drayton said the video showed Letecia and Gannon Stauch get into a red pickup truck in the driveway of their home around 10:15 a.m. About four hours later, the truck returns to the house and Leticia Stauch gets out of the vehicle alone.

The El Paso County Sheriff's Department has a copy of the video, but a spokesperson cautioned the video was only one part of the investigation.

"This is just one piece in a very, very, very large puzzle," spokeswoman Jackie Kirby told ABC News Tuesday morning.

Drayton said he showed the video to the boy's father Sunday.

"He just broke down crying and said, 'she lied. She lied about the time. He didn't go to a friend's house,'" Drayton said.

Leticia Stauch denied having anything to do with the boy's disappearance and said her family has received death threats since the boy's disappearance.

"I took care of Gannon for the last two years in our home. I would never, never, ever hurt this child," Stauch said.

Authorities on Monday night searched a new area about 10 miles from where the boy vanished, but heavy snow complicated efforts.

Voter registration evidence shows that Gannon's biological mother previously lived in Fayetteville and Wilmington in North Carolina. His step-mother lived in South Carolina most of her life, but did stay for some time in Robeson County, Pembroke and Lumberton. His father has previously lived in North Charleston and Horry County in South Carolina.

ABC News contributed to this report.