“Um, wait one second,” said the detective, coming to grips with the disaster. “Your honor, I think I’m remembering the wrong murder…”

That spells mistrial with a capital M.

Many detectives prefer to take the file onto the stand, but with some judges that can be dangerous. A typical case file contains notes and reports on potential suspects and blind alleys that were eventually discarded, and a few judges will allow a defense attorney, on cross-examination, to take hold of the file and go fishing. Given an alternate suspect from a police file and a tolerant judge, a defense attorney can run for miles in front of a jury.

One detective, Mark Tomlin, makes a point of copying his trial notes onto the back of the defendant’s computerized arrest sheet. Once, when Tomlin was testifying, a defense attorney asked to see his notes and began to suggest that they be admitted into evidence. He then turned the sheet over, looked at his client’s priors, and returned it without another word.

Veteran detectives also go into court knowing the strengths and weaknesses of their cases; they can anticipate a defense attorney’s line of questioning and answer accordingly. This doesn’t mean responding with answers that are grandly deceptive, but tailoring answers so that they do the least damage. If, for example, the defense counsel knows that your witness picked his client from a lineup but failed to do so in a photo array the previous day, he’s almost certainly going to ask about that. Anticipating, a good detective will, in the course of his answer, manage to work in the fact that the array used a picture of the suspect that was six years old, that the suspect’s hair was different, that he had no mustache and whatever else can be said before the lawyer stops him from talking. Defense attorneys have now endured untold generations of slick, manipulative police witnesses; one consequence is the just-answer-yes-or-no style of cross-examination, which requires a detective to wait for the prosecutor’s redirect to fully shape his answers.

On the other hand, if a detective is on the stand and not sure just where a defense attorney is going, his answers will become cautious and a little less specific, though not inaccurate in any detectable sense. A professional witness doesn’t needlessly back himself into corners with blanket declarations and assurances, because a good attorney will then manage to produce an exception.

“Detective, you say that after Mr. Robinson was arrested for this crime, the robberies in the area of North and Longwood ceased.”

“Yes, sir.”

“Detective, may I call your attention to a police report dated…”

Experienced detectives take one other rule to the stand with them: They don’t lie. The good ones don’t, anyway, not about anything that could ever be directly contradicted in open court. Perjury can destroy a career, steal a pension, and maybe, if the lie is big enough and stupid enough, lead to some jail time. For a detective to falsify evidentiary material, to wrongly attribute statements to suspects and witnesses, carries a risk far greater than the reward. How much does it matter-really matter-to the detective if any one suspect charged with any one murder goes to prison? He does fourteen of these guys a year, a couple hundred in a career. For what reason is he going to start believing that the world ends when he doesn’t win a case? If it’s a police shooting, or if it’s someone the cop knows, then some corners might be cut, but not for something that happened in the 1900 block of Etting Street on a Saturday night last summer.

The one notable exception to the marked honesty of a good police witness, the only point in the legal process where law officers can be expected to lie routinely or, at the very least, exaggerate, is probable cause.

For narcotics or vice detectives in particular it’s become a ridiculous game, this business of establishing the correct legal prerequisites for a search or arrest. Not surprisingly, it isn’t enough to say that the suspect was a squirrel who’d been out on that corner about ten minutes too long. No, the law of the land requires that the arresting officer had the opportunity to observe the defendant operating in a suspicious manner on a corner known for drug trafficking and that upon closer inspection, the officer noticed a glassine envelope sticking out of a sweatshirt pocket as well as a bulge in the front waistband indicative of a weapon.

Yeah. Right.

Probable cause on a street search is and always will be a cosmic joke, a systemic deceit. In some parts of Baltimore, PC means looking at a passing radio car for two seconds longer than an innocent man would. The courts can’t acknowledge it, but in the real world you watch a guy until you’re sure he’s dirty, then you jack him up, find the dope or the gun and then create a legal justification for the arrest.

In homicide, where the name of the game is search-and-seizure, with affidavits written in advance for specific addresses, the PC generally has to be straight up. After all, you need the judge’s signature on the warrant just to get you inside. A detective with a talent for the written word may be able to get some weak or exaggerated PC past a duty judge, but at least he’s required to put something in the affidavit.

For the homicide detective, the only real moment of equivocation on the stand occurs not over the issue of probable cause, but when a defense attorney asks whether his defendant’s statements were coerced, or whether his client asked for a lawyer before making those statements. In his heart of hearts, a good detective knows that every statement is, to some degree, the result of coercion if not outright fraud. But, holding to a strict legal definition, he can answer in the negative and call his testimony something other than perjury. After all, the defendant got his rights, he signed his Form 69. He had his chance.

“But did he want a lawyer?”

Well, a detective could ask, how do you define want? Probably half of all suspects get into an interrogation room and say they want a lawyer, or they might need a lawyer, or maybe they should talk to a lawyer. If they stick to it, if they really want that lawyer and they don’t want to talk, then the interrogation is over. But any detective worth his salt tries-for a time, at least-to convince them otherwise, content in the knowledge that there isn’t a Supreme Court justice standing outside the interrogation room door.

“Did my client ask for a lawyer?”

“No, he did not.”

On the stand, the last rule for a homicide detective is that nothing is personal-nothing between the detective and the defendant, nothing between the detective and the lawyers. On the stand, demeanor counts. A cop who loses his cool long enough to display contempt or malice for the defendant or his counsel provides the jury with the image of a malevolent system, of a crusade rather than a prosecution. The defense attorney calls you a liar, you impassively deny that. He declares your investigation to be incompetent, you deny that, too. His client eyefucks you from the trial table, you ignore it.

For a veteran detective, there is nothing hard in any of that. After all, if it’s the ordinary homicide case, the indifference is probably genuine. But even when the case matters, a veteran doesn’t do anything to make the defendant believe that he cares, or that the outcome of this case has any relevance in any world that rates. In its way, it’s an attitude that offers the defendant even less than anger or contempt. In court, a detective’s message to the defendant is clear and unmistakable: Win or lose, you’re still a piece of shit living on the margins. If the jury comes back guilty, you’re down for some years; if the jury doesn’t do the job, you still don’t count. Six months from now, you’ll be back in city jail on another charge, says the attitude. Either that or someone on my shift will be out there one night chalking your ass off.