Roy Kerry is an alternative medicine practitioner (he runs the Advanced Integrative Medicine Center in Portersville, Pennsylvania), member of the American College for Advancement in Medicine (a pseudomedical organization), and one of the foremost champions of chelation therapy as a treatment for autism. Now, chelation therapy, in addition to being ineffective against autism, is a rather dangerous affair, and in 2006 a boy died during a chelation therapy regime administered by Kerry, which finally led officials to scrutinize the use of this particularly insidious treatment. Kerry (who was an M.D. at the time) had his license temporarily suspended, was barred from chelating children under age 18 in the future, and sued by the victim's parents (the suit was settled in 2010 with payment of an undisclosed sum). At least the case is one of many counterexamples to people who are prone to claim that although alternative therapies may not have been proven to be efficacious, at least the do no harm.
Kerry, in this case and others, is apparently convinced that autism is linked to heavy metal poisoning, and admitted to using bogus tests in this case to back up his diagnosis.
Diagnosis: Living proof of the fact that alternative treatments are actually directly harmful (and not just that accepting them poses a long-term danger). Kerry is still afoot, however.