By Oren Liebermann

PHILADELPHIA (CBS) – The next test for students at St. Joseph’s Prep school won’t require a pen and paper – it’ll take a single strand of hair.

“Our hope is to educate them and treat them individually with respect,” says Principal Jason Zazyczny.

The school will start randomly drug testing 20 students a month in March – not because of any specific incident at the school, but to combat teen drug use in general.

“We’ve been very transparent with what we’re doing – we want them to be successful, we want them to know we care, we want them to know that what we’re doing is what we feel is in their best interest,” agrees Bill Gillespie, the director of counseling.

Administrators say their goal is to help students, not expel them. The first failed drug test leads to counseling.

Mayor Michael Nutter — a St. Joseph’s Prep alum — stands behind his school’s program.

“We need to acknowledge the reality that, unfortunately, some of our young people — regardless of where they go to school — may have challenges with drug issues,” Mayor Nutter says.

“It’s a non-punitive policy, so we’re going to do everything possible before we would ever ask a student to withdraw,” adds Principal Zazyczny.

Students like senior Tom Coar say random drug testing goes too far.

“I’m not okay with it. I think it’s overstepping some boundaries,” he says.

But parents support the program, and the effort to help kids in need.

“I don’t think it’s invading their rights in any way. I think that the school has a greater interest in protecting all the students,” says parent Maggie Soboloski.

The school will test about 60 students before the end of the school year, at which time they will evaluate the success of the program.