A revolver was recovered Wednesday at Samuel Fels High School after authorities received a tip a male with a gun was in the building.
An 18-year-old student was taken into custody, School District spokesman Fernando Gallard/
"Besides facing possible criminal charges, the student will be referred to expulsion," Gallard said.
A lockdown of the 1,100-student school at 5500 Langdon St. in Philadelphia's Crescentville section was being lifted in phases.
The school was placed on lockdown when a student reported another student had a weapon in a backpack inside the building, Gallard said.
After an hours long search, officials said an unloaded revolver had been found in a trash can in the weight room.
No charges were immediately announced and authorities said the investigation was continuing.
It was the second gun-related incident at the school this week: On Monday, the high school was placed on a temporary lockdown after a report of a firearm in the building. No weapon was found.
This is a developing story. Check back for more information.