Inside Undercover Narcotics Work: Lessons for Today's Defense Attorneys

I spent more than a decade running narcotics cases for the Miami Police Department. The case-construction playbook is consistent across most agencies in South Florida. A confidential informant (CI) is developed — often a person facing their own charges who has been offered consideration in exchange for cooperation. The CI introduces an undercover officer (UC) to the target. The UC makes one or more controlled buys. After the controlled buys, depending on the case strategy, the case may close to arrest or may proceed up the chain — the UC asks the target to move larger weights, to introduce them to suppliers, or to participate in transportation.

Every step of that process is documented in agency reports — and every step has known seams the defense can pressure.

The CI is the foundation of most cases. Their reliability is what justifies the investigation. The defense's first investigative priority is documenting everything about the CI: their criminal history, their charges at the time they began cooperating, the consideration they received, any payments, any prior cases they have worked, prior cases in which their testimony was credited or discredited, and their personal motive to produce the result the agency was looking for.

Florida is generous in discovery on these points compared to federal practice — Giglio material on CI deals is generally available pretrial. The investigator's job is to push for full discovery on the CI, then independently corroborate or contradict the CI's prior reliability through public records and interviews. CIs lie to officers about everything from prior cooperation to their own continued drug use. Documenting those lies is straightforward and devastating in court.

Florida recognizes both subjective and objective entrapment defenses. Subjective entrapment requires showing the defendant was not predisposed to commit the offense and that law enforcement induced the conduct. Objective entrapment — also known as outrageous government conduct — does not require the predisposition analysis and looks instead at whether the government's tactics were so improper they violate due process.

Both defenses depend on documented investigative facts. How was the target identified? Did the CI seek the target out or vice versa? How many overtures did the UC make before the target agreed to a transaction? Were there refusals? Was the target supplied with the means to commit the offense? Did the operation continue after the case could have closed?

An investigator working a narcotics case for the defense documents the full investigative timeline — through discovery, witness interviews, and where appropriate Florida public-records requests on prior agency operations — to assemble the foundation for the entrapment argument.

Narcotics evidence travels through multiple hands. UC officer collects from the target. UC delivers to the case agent. Case agent transports to the property room. Property room logs in. Lab pickup. Lab analysis. Lab return. Trial transport.

Each transfer is a chain-of-custody link. Every link has documentation and timing. Defense investigators pull the property-room logs, the lab logs, the agency transport records, and the lab analyst's bench notes. Chain-of-custody errors are surprisingly common — substance weights that change between logging events, gaps in custody, transcription errors on lab forms. We document them.

Most controlled buys are audio-recorded, often video-recorded. The recording is the state's exhibit. It is also the defense's exhibit. We listen to every minute of every recording — not the transcript, the actual audio.

Recordings frequently show: the UC providing the substance to the target rather than the reverse; the target expressing reluctance the agency report did not document; coaching from the UC on what to say; recording-quality gaps at critical moments; or context that puts a recorded statement in a very different light than the prosecution's narrative.

The state's transcript of a recording is the state's interpretation of the recording. The defense should never accept that transcript without an independent listen.

When a case is part of a larger operation, the same UC, the same CI, and often the same evidence-handling chain are used across multiple defendants. The discovery in your client's case is the discovery in the co-defendant's case. The defense investigator should be aware of every parallel case and pull the cross-case discovery — because inconsistencies between cases involving the same officers and the same CI are powerful impeachment material.

We have located inconsistencies between the same officer's testimony in two different cases tried in the same courthouse the same month. The state had not noticed. The defense did.

A serious Florida narcotics case is not a case to defend with discovery alone. It requires an investigator working in parallel with counsel from the moment of arrest, pulling everything I described above and more. Most of our criminal defense work in Miami-Dade involves narcotics-related charges, and we have built the case-construction process around the exact seams I have outlined.