Opening arguments in a federal civil trial centering on a Chicago police officer who allegedly shot his best friend in the head, crippling him for life, were concluded Tuesday morning.The family of plaintiff Michael LaPorta is seeking $90 million in damages from the city of Chicago for allegedly allowing officers like Patrick Kelly to act with impunity and never receive punishment for his misconduct. The city maintains LaPorta tried to kill himself using Kelly’s service weapon after a night of drinking in January …