Glendale Heights police responded just after 4 a.m. Tuesday to the 400-block of James Court for a reported shooting.
Fernando Cardoso had been handling a Smith & Wesson .45 caliber handgun in his bedroom, when it fired, police said.
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The bullet went through his bedroom wall into the living room, hitting a family member sleeping on the couch.
The family member was treated and released from Good Samaritan Hospital.
Cardoso possesses a valid Firearm Owner's Identification card.
He was charged with reckless discharge of a firearm in connection to the incident.