There are different types of dirty cops. There are the ones who steal from people. There are the ones who use their shields to trade sex for a break. There are the ones who coerce confessions. There are the ones who just lie. The system was never crafted to deal with dirty cops, expecting cops to be honest and trustworthy, and thus entrusting them with a gun, a badge and the authority to do massive harm to human beings in the name of The People.

The irony is that it can be impossible to distinguish the good cop from the bad, not just because we can’t see what they’re doing but because they can be the same person. Cops are funny that way. Today’s hero on the news was callous and brutal to some poor guy yesterday.

There are many institutional disincentives to catching bad cops. Cops watch each other’s back for mutual self-protection, as Frank Serpico brutally learned. Prosecutors need them to bring them bodies and do the dirty work on stage. The public needs someone to call when things go bad. That bad cops exist doesn’t mean society would be better without them. We need them. And we have an incentive to believe they aren’t bad, because we need them.

But there are certain jobs, certain crimes, where the only person who would know that a cop is dirty is the person he was dirty to, the victim of his theft or rape, or the lie he told. The story has long been the same, a “he said / he said” scenario. If that sounds familiar, it is. This doesn’t only happen in campus sex tribunals, but when someone alleges a cop was dirty. Who you gonna believe, the cop or the perp? Of course the perp is going to accuse the cop since he doesn’t want to go to jail. Perps will say anything to get out of their busts, and cops save kittens in trees.

Joseph Franco was an undercover narcotics detective. He made a lot of busts, thousands of busts, and he made them in minority neighborhoods because that’s where narcs are deployed. That’s where drugs are sold on the street. There are two basic kinds of drug arrests, “buy and bust” and “observation sale.” The former involves a UC going up to someone to make a purchase of drugs, usually with pre-recorded “buy” money which means bills photocopied to show their serial number which can later be compared to bills found on the seller. There should be drugs in evidence from the buy to provide further evidence that the sale occurred and it was for drugs, as a lab test will show.

The latter involves a cop seeing a drug sale, generically described as a hand-to-hand of an object, “upon training and experience,” used to package drugs. Both of these scenarios are fraught with opportunity to lie, to manufacture evidence and to bust anyone the cops want to bust. Ultimately, it’s a matter of trust.

But why, you ask, would a cop lie? Why risk his badge, his pension, his freedom, to fabricate a crime and arrest an innocent person? It’s a good question, asked by every judge to whom these arguments are made. It’s a question that the defendant can’t answer. But it happens, and we know this not because we believe our clients’ claim of innocence, but because once in a very great while, a cop like Joseph Franco gets nabbed.

Over nearly two decades as a police officer and narcotics detective, Joseph E. Franco made thousands of arrests, many for the possession and sale of drugs. Mr. Franco often worked undercover, and his testimony secured convictions for prosecutors around the city.

But officials who once relied on Mr. Franco are questioning his accounts. After he was accused of lying about drug sales that videos showed never happened, Mr. Franco was charged with perjury in Manhattan in 2019.

Without videos proving Franco’s trusted allegations were false, he would have done his time on the job, collected his pension and, perhaps, spent his evenings regaling drunks in a seedy bar with his stories where he was the hero, gun at his hip and shield marked “retired” in his pocket. Instead, he joins former homicide detective Louis Scarcella on the list of disgraced cops, bad cops, dirty cops. And then came the consequences.

Prosecutors in the Bronx say more than 500 convictions have been or will be dismissed because they relied on testimony from a former NYPD detective now facing perjury charges in Manhattan.

District Attorney Darcel Clark said a judge dismissed 133 felony cases Thursday linked to former detective Joseph Franco, bringing the total to 257 so far. Her office’s Conviction Integrity Bureau plans to seek dismissals in more than 250 additional cases, as well.

These 500 cases come atop dismissals in Brooklyn and Manhattan, and these come after prosecutors tried their best to salvage Franco’s cases.

“We did not want to dismiss or vacate out of hand all cases he was involved in; we investigated those that hinged on his testimony and sworn statements. His compromised credibility suggests a lack of due process in the prosecution of these defendants, and we cannot stand behind these convictions,” Clark said in a statement.

If there was evidence deemed by prosecutors sufficient without Franco’s testimony to show guilt, the convictions were left intact, because nobody who worked with Franco would be dirty, or “dirty-adjacent” as might be fashionably put these days,

How many cases were made by lying cops? No one will ever know, and this isn’t to say that these were all innocent people. Indeed, there could be a significant percentage of Franco cases that were legit, tainted by Franco’s getting caught on video in a few and falling because Franco’s a liar. But for the videos showing this, no one would have believed it. And without video, no one will believe it of any other cop.

While video hasn’t been the savior of integrity we hoped, it’s done an awful lot to show what we’ve been arguing for a very, very long time. We don’t know why, in any particular case, a cop lies, but it happens and they do.  We knew it then and no one believed us. Now that there’s the occasional video, you know it too.