CHARLOTTE, N.C. -- A senior at North Mecklenburg High School was caught using drugs in her car at the start of school Tuesday, police said.

A teacher confronted her, and officers said that's when she tried to toss the drugs.

Now 18-year-old Jane Marsh is charged with felony possession of heroin. Huntersville police said she also had marijuana, drug paraphernalia and a razor blade on her.

Ricardo Torres, a drug prevention counselor, said the use of heroin among teens is extremely rare.

“The percentage is very, very minute of those who had tried heroin, but the other drugs -- alcohol was skyrocketing, tobacco and marijuana,” he said.

A recent study conducted in Charlotte-Mecklenburg Schools backs Torres’ statement. That survey, released last week, shows 40 percent of high school students in CMS said they've used marijuana, while less than 2 percent admit to using heroin.

Torres said with so many students using marijuana, a gateway drug, the door is opened to harder, more addictive narcotics, like heroin.

“They basically will start experimenting with those, and those will be the harder, more addictive drugs to get off of,” he said.

CMS Substance Abuse Coordinator John Basilice said the use of any drug by a student is cause for concern.

“Whether it is a harder substance or alcohol, any substance by any kid in our district is something we need to pay attention to and really be concerned about,” he said.

CMS has a number of preventative measures in place, trying to educate children of the risks of drug use. The district is also constantly battling substance abuse problems among students. On April 1 it’s hosting a town hall meeting at Lake Norman Baptist Church to combat alcohol use. That meeting will be from 6:30 to 8 p.m.

Police said in this case, what Marsh is accused of carrying is consistent with someone selling drugs, but so far she's only been charged with possession of the drugs, paraphernalia and a weapon on campus.

Marsh is suspended from school.

LINK: Youth Risk Behavior Assessment

LINK: More Info On Heroin