On February 10, 2005, Mark Degner disappeared from Paxon Middle School in Jacksonville, Florida, along with his best friend, Bryan Hayes. One of the boys caused a disturbance, allowing the other to leave class, and together they walked out of the school. They have not been seen since. Initially, authorities believed Mark and Bryan had run away and remained in the local area. However, as time passed with no sightings or contact, and considering their medical conditions, their case was reclassified as endangered and possibly involving foul play. Mark has developmental delays and suffers from bipolar disorder, requiring daily medication. He has a distinctive nervous tic, frequently shrugging his shoulders and blinking his eyes when anxious.