The best crime-stopping policies actually deal with criminals. Yet Heather Mac Donald (“Fighting Crime Where the Criminals Are,” Op-Ed, June 26) wants the New York Police Department to continue a stop-and-frisk policy with a 90 percent failure rate. Nearly nine out of every 10 people stopped and interrogated on our streets are let go without a citation or summons — and certainly without an arrest. Last year, N.Y.P.D. officers stopped New Yorkers 575,000 times. A gun — the ostensible reason for the stop-and-frisk regime — was found in slightly more than 0.1 percent of those stops. That is an unbelievably poor yield rate for such an intrusive, wasteful and humiliating police action. I agree with Ms. Mac Donald that vulnerable communities need better police protection — but a policy that is both ineffective and hurts the long-term relationship between the police and the community is not the way to provide that protection.