(Memphis) For the third time in a week, a weapon was found at Fairley High School.
The school district and principal are asking parents to help them stay vigilant.
Since Monday, three Fairley High students have left school in handcuffs after being arrested for bringing a weapon on campus.
This time, school security officers saw a 17-year-old stuff something in his pocket before going through a metal detector.
They searched him and found a fully-charged black Taser.
On Thursday, a .40-caliber handgun, ammo, and a bag of marijuana were found in a locker.
Eighteen-year-old Curtis Walton was arrested and admitted the items were his.
On Tuesday, it was a 16-year-old who left school in the back of a squad car after bringing an unloaded .22 to school in his backpack.
Shelby County Schools say they know parents are concerned, but what they should know is in each of those cases this week, the system put in place worked - either they got a tip from another student or the metal detector spotted it.
In a letter to parents, the principal asked for help from home, too.
She says the school is trained to catch these weapons but they want parents to talk to students about the consequences of bringing weapons to school.
The district says metal detector checks are no longer random in its middle and high schools - they are routine.
A Kirby High School student was also charged Thursday with carrying a weapon on campus after he was caught with a knife.