JACKSON TWP — The township police chief Monday said his department is investigating an incident in which a Seneca Valley High School senior allegedly sold marijuana brownies on campus.

Chief Terry Seilhamer said a 17-year-old senior allegedly mixed about $140 worth of marijuana into a batch of brownies and began selling them Thursday for $15 each. That student along with an 18-year-old friend, also a senior, allegedly baked the brownies at a house Wednesday night.

At least four juniors at the high school bought the brownies, and at least one of them became sick at school, according to Seilhamer, That student then texted his mother and admitted eating the brownies.

Seilhamer said his office was contacted Thursday afternoon by the high school principal, who was interviewing the students.

The chief said all of the students involved will face charges, although only the 18-year-old will likely face charges outside of juvenile court. The students also are likely to face school sanctions, he said.

Seilhamer said the two students allegedly involved in making the pot brownies could face charges of delivery and possession of a controlled substance, manufacturing a controlled substance and criminal conspiracy.

The four students who consumed the brownies could face charges of simple possession, he said.

However, the students could face more serious charges because the incident took place on school grounds.

“All of this was on school grounds so that exacerbates the issue,” Seilhamer said. “Any time you possess drugs on a school campus there could be an enhanced sentence.”

Linda Andreassi, director of communications for Seneca Valley School District, said school officials are working with police to resolve the matter.

“Beyond that, because the investigation is ongoing, we are limited in the amount of information we can share at this time,” she said. “It’s important to note, though, that consequences will be assigned to all those involved. Our hope is that this will serve as a reminder to our students that substance use/abuse seriously impairs the ability of individuals to develop their full academic and social potential, and adversely impacts the educational environment.”