Are charter schools bad at special ed?

Jay Matthews:

Critics say public charter schools have an unfair advantage over regular public schools because they are less likely to have students with learning disabilities. That is not always true. Consider one D.C. charter management organization, DC Prep, with more than 1,000 students.
Its Edgewood Middle Campus, a fourth-through-eighth-grade middle school, has a larger portion of special education students than the District’s average. Seventeen percent receive services and are showing progress.
I do not mean to disparage regular D.C. schoolteachers who are doing special education work. I have seen enough programs for students with learning disabilities to know that fine work can be found at schools otherwise labeled as failing because of their low test averages.
Emily Lawson, founder and chief executive officer of DC Prep, describes her school’s methods this way: