965 KILLED BY POLICE IN 2015

Here is the Washington Post's data on persons killed by police in 2015.  It's 2-3 people per day.This is probably the best data available.   The "official statistics" show less than a third of this figure.  90 Individuals were unarmed.  However, this does not automatically make the shootings unlawful. Some undoubtedly were illegal, but we have no easy way to make that determination.
"In a year-long study, The Washington Post found that the kind of incidents that have ignited protests in many U.S. communities — most often, white police officers killing unarmed black men — represent less than 4 percent of fatal police shootings. Meanwhile, The Post found that the great majority of people who died at the hands of the police fit at least one of three categories: they were wielding weapons, they were suicidal or mentally troubled, or they ran when officers told them to halt."  Not all of the majority category are going to be lawful and

While 4% is not a not a big percentage,  that's about 38 people whose lives may have been taken unlawfully.