The family of missing Florida schoolteacher Steven Stark is deeply troubled by his sudden and unexplained disappearance.
UPDATE: Alex De Armas, the girlfriend of Stark's son, Adam Stark, said the family does not feel Steven Stark "is in any danger." De Armas said she will notify the media if anything changes.
"Everyone is just sick with worry," Tracey Carol Merrill, the sister of Stark's ex-wife, told The Huffington Post.
According to Merrill, family members last heard from Stark, a 62-year-old teacher at Citrus Cove Elementary School in Boynton Beach, on October 20. That day, he called in sick to work for the following day. On October 22, when Stark missed work without calling, his family was notified.
"The authorities went to his home to check on his welfare and all they found was his cell phone on the counter," Merrill said. "Nothing was out of place. His clothes were not missing, [but] his truck was not there and he was gone."
On Tuesday, Adam Stark, the missing teacher's son, told WPBF it would be out of character for his father to take off without notifying someone.
"He is always on time," said Adam Stark. "He's a very punctual person. In 30 years, he's never not called or not showed [up for] work."
Adam Stark did not respond to a request for further comment from HuffPost on Thursday.
Merrill described Steven Stark as "sarcastic," "funny" and "witty."
"He always has a smile on his face," she said. "[He is] full of laughter. I can't remember a single time where he was ever in a bad mood or raised his voice in anger. He's a really good guy."
The only clues to Stark's disappearance are several debit card transactions that police say occurred in St. Johns County this week, most recently at a Publix supermarket on Wednesday afternoon.
"Our detectives confirmed it was him that used the card and not someone else," Kevin Kelshaw, a spokesman for the St. Johns County Sheriff's Office, told HuffPost.
Despite that revelation, family members remain concerned about Stark's safety.
"It doesn't mean there wasn’t someone forcing him to make that transaction," Merrill said. "Criminals are getting smarter and smarter all the time."
Stark's 2006 blue Dodge pickup, with a Florida license plate HO10MQ, is also missing.
"None of it sits well with me," Merrill said. "I fear the worst [but] am hoping for the best."