ST. PETERSBURG, Fla. (WFLA) — A Florida Missing Child Alert has been issued for Allister Nasr as St. Petersburg police continue to search for the 17-year-old who was last seen near 62nd Avenue North.

On Friday, Allister’s family was knocking on doors and handing out flyers near where police said they found Allister’s bike on Wednesday.

“It definitely gives us the promise that he would be alive,” said Avicenne Nasr, Allister’s brother. “It’s been hard to sleep for all of us. My dad is still sleeping downstairs waiting for Allister to hopefully return home.”

Police said Allister was last seen on March 1 leaving his home near Bayou Grande Boulevard Northeast. He was carrying a black backpack that police said he later dropped off at a school nearby and switched to a red backpack.

The founder of A Voice for the Voiceless, an organization spreading awareness of those who are missing, spoke about this detail in the case.

“Even if someone switches a backpack or does something like that, we don’t know where they’re going to and we don’t know what’s calling them to that place,” said Whitney Sich, the founder.

On Friday, the family said police told them Allister was seen an hour later on surveillance at the Weedon Island guard gate. He was still wearing the red backpack and walking the bike.

Avicenne described the note Allister left, saying it described an internal struggle. It made law enforcement consider Allister to be endangered and worried for his personal safety.

“Definitely with senior year, I believe that he, with the anticipation of going to college, waiting on those acceptance letters definitely stressed him out a lot,” Avicenne said. “The note was overall very concerning. When I read it, I was a bit shaken. It was extremely in his mind.”

Sich asks that everyone remain vigilant and keep an eye out for Allister.

“Obviously Allister needs help. He needs somebody to be there for him or help find him. I think that we all still need to be concerned and looking for him,” Sich said.

The family wants to send a message to Allister saying they love and miss him. They are also asking people to check their dashcams and call St. Pete police if they find anything.