Dr. Craig Haytmanek performs a dissection with some students at the Medical Academy Charter School in Catasauqua on Friday, September 27, 2013.

In four half-hour sessions, Haytmanek allowed students to slice into a pig's heart and lungs. He drew a diagram of a heart on a white board.

Students wearing the school's uniform — purple polo shorts and khaki pants — donned surgical gloves and sliced into arteries. They reached inside and dug out crimson blood clots.

It was the second such lab this year, Hughes said. Labs don't correspond to specific coursework; rather, Haytmanek asks the students what they want to see at the end of each session. Next week, he told the students, he'd dissect eyeballs.

According to the letter-writers, the school lacked the necessities for a good science program. The biology room had no sink or eyewash station, they said. Basic chemistry supplies didn't arrive until the second half of the year. The letter also takes issue with the rigor of the courses offered.

"Many of the courses were remedial in nature or watered down to meet the level of students left attending MACS," the letter says. "Although this is certainly not to [put] blame on the students, it presents a false image to the community to say that MACS is academically rigorous in comparison to other area schools."

Marie Reph said her daughter Brinn, a Medical Academy junior, has some classes that are far below her grade level. Reph said she expected the school to "challenge her in some way."

Konrath said his daughter also felt the academics weren't rigorous enough. He'd received assurances that the district would offer honors and Advanced Placement courses. An ad the school placed in the July 28 edition of The Morning Call says it offers "all standard high school subjects taught including honors and AP courses."

But such courses aren't being offered, according to the letter.

Hughes said that's true, but it's because Medical Academy decided not to offer Advanced Placement classes after finding few of its students would qualify. She said they have made the curriculum more satisfying for advanced students and hope to be able to offer AP classes in the future.

'Potential violent behavior'

In June, the Medical Academy Charter School canceled its last day of class. Konrath said he never heard an explanation from the school.

He heard rumors, though: "They got a lot of threats because they got rid of a lot of teachers," he said.

According to the letter, "the last day of school was canceled due to potential violent behavior on the part of our students." The letter alleges students were angry about the departure of the bulk of the school's staff. They "threatened to physically harm Ms. Hughes."

Hughes said school was canceled because "it was in the best interest of students." She said students were upset after the departing teachers chose to tell their classes that they were leaving.

"I thought it was unprofessional for teachers to tell students," Haytmanek added.

Until January, the school had no discipline system in place, the letter said. In January, an educational consultant helped the teachers draft a demerit system. But the administration never followed through on punishments, the letter said.

"This resulted in a chaotic learning environment and low teacher morale," the letter reads. "Students essentially realized that they were in control and that all consequences were empty threats."

Konrath and Reph both say they visited the school and observed profane arguments among students.

Hughes said the district has a disciplinary plan that's spelled out in the student handbook.

While Medical Academy Charter School didn't expel anyone during the 2012-13 school year, it required a small number of students — fewer than 10 — to depart the school for failing to live up to academic standards, she said.