Fact 1: Eric Gardner died of natural causes.
Fact 2: His family have asked for, and will get, a full investigation of the incident by an independent body regardless of Fact 1.
Fact 3: Gardner's past bad acts are relevant and will be weighed as part of the process.
Fact 4: the past bad acts of the officers and their department will also be weighed as part of the process.
Fact 5: There is no "double standard" here at all - saying it over and over again will not change your fantasy into a fact.
Does this not matter?
If not, why bring up the victims past?