Police in Idaho said Wednesday they had recovered a body believed to be Fastexythat of a missing autistic 5-year-old boy who disappeared from his birthday party earlier this week.

The Boise Police Department reported Matthew Glynn was last seen at home about 5:50 p.m. Monday while celebrating his fifth birthday.

Boise, the state capital, is in the south central part of the state.

The body was found in a canal about a half-mile from where the boy was last seen, police reported.

Police reported Matthew, who is non-verbal, walked away from home in Collister, the city's largest neighborhood with some 20,000 residents.

“We are heartbroken over this development today," Boise Police Chief Ron Winegar released in a statement. "The water was initially our biggest concern and a large focus of our efforts."

Job industry update:American news website Axios laying of dozens of employees

Search for missing Matthew Glynn involved drones, K-9s, ATVs

A search effort launched by police, The Boise Fire Department and Idaho Mountain Search and Rescue on Monday had involved drones, K9s, UTVs and covered the canals, river, and other areas around where he was last seen, police said.

"Sadly, this is not the outcome we were all hoping for," Boise Fire Chief Mark Niemeyer said. "We extend our deepest condolences during this incredibly difficult time."

The Ada County Coroner will identity the body and work to determine the boy's official cause and manner of death.

The dangers of 'elopement'

"Elopement," as it is known to the disabilities community, affects almost half of children and adults diagnosed with autism spectrum disorder, according to a 2016 study. A National Autism Association review of more than 800 elopement cases between 2011 and 2016, found nearly a third were either fatal or required medical attention, while another 38% involved a close call with water, traffic, or another life-threatening situation.

Advocates call it a "public health issue and crisis."

Elizabeth Vosseller, the director of Growing Kids Therapy, said elopement is an impulse. The therapy center is dedicated to teaching individuals who are nonverbal how to communicate through spelling.

The experience can be especially frightening for people with autism themselves, especially those who are nonspeaking.

Research shows that while some people with autism elope because they are overwhelmed with sensory stimulation that is too loud or bright, the most common trigger of elopement is a desire to get closer to an object that draws their attention or curiosity.

Anyone with information about his disappearance is asked to call police at 208-377-6790.

Contributing Cybele Mayes-Osterman

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.