At College Preparatory Academy, it started with a demerit. If a student talked back, teased another student or wasn't following the public charter school's policy on uniforms, he or she would get a demerit, worth 30 minutes of detention to be served after school. More demerits, more time.

But if the student blew off detention, he was suspended. Usually for just one day, said Susan Schaeffler, CEO of KIPP DC, which runs College Prep and nine other schools in the District.

Disciplining the students
School Grades Number of students expelled Percentage of students expelled
Friendship Public Charter School - Collegiate Academy 9-12 56 5%
Kipp DC Public Charter School - College Prep Academy 9-12 17 5%
SEED Public Charter School 6-12 13 4%
Friendship Public Charter School - Tech Prep Academy 6-10 11 3%
Center City Public Charter School - Trinidad Pre-K-8 7 3%
Students suspended or expelled
School Enrollment Number of incidents Number of students with incidents Percentage of students with discipline incidents
Maya Angelou Public Charter School (middle) 210 552 147 70%
Kipp DC Public Charter School - College Prep Academy 330 442 194 59%
SEED Public Charter School 340 266 166 49%
Friendship Public Charter School - Tech Prep Academy 378 406 173 46%
Maya Angelou Public Charter School (high) 296 239 121 41%

That's how College Prep ended up suspending at least 54 percent of its students last year, according to data released by the DC Public Charter School Board last week. Most students were suspended for just one or two days.

But other students didn't learn their lessons and brought knives or drugs to school. The charter expelled 17 students, or 5 percent of its population, in the 2011-12 school year.

"It's our responsibility to make sure our students are safe, and our parents are expecting that every day," Schaeffler said. "The day we don't do that, we have a really big problem on our hands."

Ten D.C. charter schools suspended at least one-third of their students last year, and suspended some of them, racking up numbers that have drawn questions from parents and community members over whether children who act out can afford to lose class time.

The charter schools' discipline policies also have drawn scrutiny from D.C. officials over whether the schools are dumping their problem kids back into D.C.'s traditional public schools. The traditional school system is preparing a report on how many students transfer midyear from the charter schools, after the D.C. Council held a hearing on the issue in February.

But charter leaders say their discipline policies are part of what makes them charter schools: autonomy to decide what's acceptable on their 100-plus campuses and how to best provide students' education.

For instance, of SEED Public Charter School's 340 children, 13 were expelled last year, and as many as 166 students were suspended -- meaning about half of all students were kicked out of school, temporarily or permanently. But SEED's charter allows it to act as boarding school, keeping kids overnight five days a week.

"We have a larger denominator for bad behavior to occur because our young people are with us 24 hours a day," SEED Head of School Charles Adams said.

A DC Public Schools student who drinks alcohol at 8 p.m. on a Wednesday might get in trouble with his or her parents, but a SEED student would be at school at the time, and would likely be expelled. "We have a strict policy when it comes to drugs, alcohol. It's not taken lightly."

But critics contend that sending students home -- particularly at such high rates -- isn't the best way to send a message about behavior.

"Suspension, and definitely expulsion, is always a sign of a school's failure to solve problems for a child," said Judith Sandalow, executive director of D.C. Children's Law Center. "We want them in class, learning. Behaviors that are causing suspension should be seen as symptoms of a disease, and you need to find the right cure for the disease, not just treat the symptoms."

Each charter sets its own discipline policy. Scott Pearson, executive director of the Public Charter School Board, said some schools may need to re-examine theirs. But he also testified against a citywide discipline policy proposed by the Office of the State Superintendent of Education, stressing the importance of allowing each charter school to set its own course.

At College Prep, for example, 425 suspensions among 330 students sounds like a lot. But 84 percent are one-day suspensions that the school uses to set up conferences with parents.

"It's clear that we do it, suspend students, more than other schools," Schaeffler said. "But it's an opportunity to get everyone together and say, 'What do we need to do, as the adults in this child's life, to get them on track?' We focus on the small things so the big things never happen."