On a May day five years ago, in the morning gloom just before daybreak, Ariel Poholek awoke in his small townhouse in the Florida Keys to find his oldest son, Daniel Weisberger, straddling him with a knife. As Poholek begged for his life, he told his 17-year-old son he needed to live to care for his younger son. Daniel said it was too late. He’d already killed his 14-year-old brother in the bedroom they shared, just down the hall.

The tragic murder followed years of anguish for Daniel, whose struggle with mental health started when he was just five and worsened as he endured a decade-long custody battle between his parents.

In this four-part podcast series, we take a look at mental illness and the criminal justice system through Daniel’s story, from Boy Scout and beloved older brother to savage killer. We rechart his troubled childhood, complicated family and downward spiral. We then head to trial, where Daniel’s high-powered Miami defense attorneys will try to convince a judge to find their client not guilty by reason of insanity in a Key West courtroom.

This story started as a cautionary tale. But its end is far from expected.