Normally a day of celebration, December 19, 2015 was the day Zachary Briley's mother marked her son's 23rd birthday with a call to the Long Beach Police Department to report him missing.
"Everywhere I go, I think I see him. But it's never him," Allison Briley told Dateline NBC. "Because of his disability, he's probably being taken advantage of. I just have such a bad feeling."
Zachary disappeared from the independent living center complex where he's resided since August 2015. The complex is run through the Harbor Regional Center's H.O.P.E Program. According to his mother, Zachary is developmentally disabled and has the mental capacity of a 10 or 11-year-old. He has reportedly been in special needs classes since elementary school.
Several conflicting stories have emerged regarding the morning Zachary disappeared. The last time he was seen that Saturday morning was after having an altercation with his duplex neighbors, a disabled couple in the same housing program. Police were reportedly called to the duplex after Zachary allegedly began banging on the couple's windows and accusing them of stealing his wallet and cellphone. Officers arrived and defused the situation. Zachary returned to his apartment to sleep, his mother told Dateline.
Allison Briley says she was having a hard time reaching her son that day, so she drove from her home in Los Angeles to pick him up, as it was his birthday.
She says she found her son's apartment door open, with his belongings strewn around his room. But the only item of note missing was a brown suede jacket she believes he was most likely wearing when he disappeared. Most of his clothes were still there, along with a recently-purchased duffle bag.
"He hasn't accessed his bank account, hasn't contacted anyone. He was so looking forward to spending time with his brother who was getting home from college that Saturday. They are so close and we were going to celebrate," says Allison.
Neighbors reportedly told police Zachary was spending time with several known drug addicts prior to his disappearance, an accusation his mother Allison adamantly denies.
Officials with the Long Beach Police Department tell Dateline there is no indication of any foul play and have classified the disappearance as voluntary. One neighbor reportedly saw him with a bag leaving the area at 8:00 that morning.
"Detectives continue to pursue all leads," an email to Dateline from the department reads. "No additional details are available."
Allison questions the events the morning her son disappeared. She says another neighbor told her that, while walking his dog, he spoke with Zachary around 8:30 a.m. and that Zachary headed toward the beach. He wasn't carrying anything with him, the man said.
Allison Briley says she is concerned that others may not be telling police the full truth.
"All these things I've found out are very concerning," Allison told Dateline. "Regardless, a special needs person needs help. It doesn't matter how old they are. I know in my heart he's not OK, no matter what happened."
Zachary Briley is described as 5'11" tall, weighing 135 lbs. with brown hair and brown eyes.
If you have any information regarding Zachary's whereabouts, please contact the Long Beach Police Department's Missing Person Investigations at (562) 570-7246.