In Canada, prosecutors are using suspects' own rap lyrics to win convictions

Before he was convicted of first-degree murder, Lamar Skeete recorded a four-part rap song inside Toronto's notorious Don Jail. It spoke of the squalid conditions, the drug use, and the violence inside the aging jailhouse.

But it was a line in the second segment of the song that was of particular interest to his prosecutors

People like him, he rapped, “don’t crack to the coppers.”

Skeete stood accused of fatally shooting a man named Kenneth Mark in 2009 outside a pizza and wing shop in Toronto’s west end. The two had had a tangled history and prosecutors had concluded that this was a crime of revenge because Mark had identified Skeete and his...