STOCKHOLM (AP) — Former NHL player Mike Danton was sent to prison for plotting to take a life. In his return to professional hockey, the skills he learned in jail may well have saved one.

Danton, who served a five-year jail term for conspiracy to commit murder, was playing in his first game with Swedish third-division club Ore on Sunday when his linemate Marcus Bengtsson hit his head on the ice after a hard hit and started convulsing.

Using the first-aid training he received in prison, Danton dropped to the ice as well, waited for Bengtsson’s jaw to unclench and then shoved his hand into his teammate’s mouth to stop him from choking on his own tongue.

Danton was convicted in a failed murder-for-hire plot in 2004, and wrote on his blog that “one of the luxuries” of his jail stint was the chance to become a certified first aid responder.

“I have seen seizures before. In prison, druggies would come in off the streets and have withdrawals,” he wrote. “So, when the convulsions did not (stop) after a couple of minutes, I knew something was wrong.”

After Danton stopped the choking, other teammates helped him put the 21-year-old Bengtsson on his side before an ambulance arrived and took him to a hospital, where he was diagnosed with a concussion and kept overnight.