A 15-year-old boy was arrested in Santa Cruz, Calif. late Monday after a body believed to be that of his 8-year-old neighbor was found in a dumpster not far from where she was last seen riding her scooter. 

Santa Cruz Police Chief Kevin Vogel told reporters that he was "confident" the body found by a detective at a Santa Cruz artist community and housing center was that of Madyson Middleton, though he stressed that no positive identification had been made. 

Vogel said the teen, who lives in the complex, was arrested at around the same time the body was found and was being questioned by authorities. KTVU reported that the boy and his family have lived at the center since 2009 and neighbors described the teen as polite and well-liked. It is not clear what, if any, relationship he had with the vanished girl. 

Madyson, who also lived in the complex with her mother, was last seen Sunday afternoon riding a new, white scooter in the Tannery Arts Center's courtyard. Her mother, Laura Jordan, said she realized her daughter was missing at around 5 p.m. local time and contacted police. 

Madyson's parents met with investigators Sunday night and again Monday at police headquarters before speaking with reporters outside.

Jordan said she's looked at surveillance video from their housing complex that watched Madyson's last minutes before she disappeared. Police have said she was last seen on video surveillance at 4:12 p.m.

Jordan walked the edges of the courtyard, and police twice conducted a door-to-door search of the entire complex, as well as a homeless resource center and shelter across the street.

Beyond the 8-acre property, searchers from throughout the state looked in boats, helicopters, on foot and bike, with dogs and cameras.

Authorities didn't send volunteers onto adjacent hiking and biking trails for fear of disturbing potential evidence, but hundreds of volunteers showed up and looked for Madyson in neighborhoods and streets.

Authorities used dogs to search nearby woods and parks and the San Lorenzo River levee. Helicopters searched the forest and the coastline, and the U.S. Coast Guard scoured the ocean 2 miles from where she was last seen.

The Tannery Arts Center, a public-private nonprofit project that includes 100 affordable loft apartments for artists and their families, a cafe, and dance and art studios on eight acres.

The property, a former leather tannery, is managed by The John Stewart Company. John Stewart, the company's chairman, said they turned the surveillance footage over to authorities Sunday night.

Site manager Warren Reed said the property is located in a very busy area, with a number of businesses and a major construction project nearby.

The Associated Press contributed to this report. 

Click for more from KTVU.com.