Although Philadelphia is not nearly as corrupt as many major cities, its police force has always had the reputation of utter corruption' a gang of bandits with badges. It's been widely believed that Philadelphia's cops are worse than the crooks and even worse than New York's and Chicago's uniformed thugs. Many, many police invent evidence. Such criminality is expected from cops.
Honest cop is an oxymoron.
Like other police, the Philadelphia cops have tampered with evidence of years. The guys at the 39th got caught at it. To their fellow officers, getting caught was far worse than tampering. Five of those who were caught are now in Federal prison for inventing evidence in drug cases. Four more are awaiting trial.