The petition also cited several fatal shootings by police officers in recent years and questioned why Alvarez did not bring charges. Among them was the 2011 fatal shooting of Flint Farmer by Officer Gildardo Sierra, who was profiled by the Tribune in 2011 for his involvement in three shootings, two fatal, over a six-month period. A dash-cam video suggested Sierra stood over Farmer as he shot him in the back, but prosecutors concluded Sierra reasonably mistook a cellphone for a gun pointed at him on a darkened street.