Truth-challenged police forensics in Baltimore

November 20, 2008

by Roger Koppl

Most people think DNA evidence is bulletproof.  Molecular biologist and forensic scientist Dan Krane has very nice presentation on some of the problems that can arise in this area.  When the biological sample is mixed, degraded, or small, the evidence can be ambiguous, which allows subjective judgment to enter.  Recent events in Baltimore point to another problem that has nothing to do with such ambiguity.

On September 27th, the Baltimore Sun reported, “In at least nine homicide, sex assault and burglary cases, Baltimore police detectives instructed crime lab technicians not to follow up on convicted criminals’ DNA found on evidence at crime scenes because they determined it was not relevant to their investigations.”  The police have a plausible explanation.  “Police spokesman Sterling Clifford played down the significance of the discovery, saying detectives routinely make judgment calls on evidence.”  Moreover, says Clifford, “Very often those crime scenes are enormous, sometimes covering entire city blocks.”  

The spokesman sounds plausible. The trouble is that the system gives discretion to one group of actors, the police, who may not always view evidence in the right light, as another story in the Sun illustrates.  A woman is killed and her ex, Randy Golden, is convicted for the crime.  Golden “was convicted on the account of a young, drug-addicted prostitute who testified that she witnessed the murder.”  Now, “a city crime lab technician had clipped fingernails from [the victim’s] body, checked them for DNA and found a match to another criminal.”  This DNA evidence was not pursued by the police, however, who (apparently) felt sure they had their man in Golden.  Nor was it made known to the prosecutor or Golden’s defense attorney.  Guess whose DNA was found?  Yep, a friend of the eye witness.  It kinda looks like the witness blamed the wrong guy on purpose to help her friend.  Notice that the legal process of “discovery” cannot reveal information unknown to the prosecution.

The problem here should be familiar to economists, namely, monopoly.  In most jurisdictions in the US we have put monopoly forensics under the control of the police.  Economists appreciate the lesson that monopoly is not generally a good idea.

I think it is important to recognize poor police decisions about DNA do not necessarily reflect corruption, ill will, or indifference to the truth.  It is the right and proper job of an investigating officer to formulate a theory of the case.  Once such a theory has been formed, the universal human disposition to confirmation bias reduces the chance that disconfirming evidence will be given adequate weight.  The issue is not getting the right people in the job, but giving them the right incentives, which is another lesson economists can appreciate.

5 Responses to “Truth-challenged police forensics in Baltimore”

  1. Bob Murphy Says:

    Great post Roger. BTW, what are your views on full-blown privatization of judicial and police services? I agree with most of your writings on this forensics stuff, but it seems to me you can’t fix the problem by just pushing it back a step. I.e. what incentives does City Hall have for listening to your recommendations, etc.?

  2. koppl Says:

    Hi Bob,

    Thanks for that comment and question.

    I’m not that keen on privatization as such. If you privatize the wrong way, you makes things worse instead of better. If you want to privatize municipal police, you need to design the market for policing services. That’s a daunting design problem, I think. How would you have both competition among policing agencies and a low probability of either collusion or open warfare?

    I would *really* like to see someone take on the job of designing a system of competing municipal police forces. How would you implement the general idea of random overlapping jurisdictions? I don’t know whether it could be done. Nor do I know whether the resulting system would involve “privatization” in any important way.

    As you know, Adam Smith attributes English common law to competition among courts. But they weren’t private courts. I think I’d like to see the idea of random overlapping jurisdictions applied to this area too, but how would you really do that? How precisely would you implement such a system? If you could do it, would the result be “private” in any interesting sense?

    We want competition to make power divided and contested. Privatization does not necessarily achieve those ends. If the competitive system is private, that’s fine. If it is not really private, that’s fine too. The question is whether power is divided and contested, but in a regular and orderly fashion.

  3. Bob Murphy Says:

    Roger,

    Well, I was trying to avoid the a-word. Since I’m worried that your analysis might just push the government-has-bad-incentives-and-information problem back one step, it wouldn’t be much better if I instead recommended that City Hall contract out the entire police department (rather than just the forensics work).

    What I meant was, have you ever considered “anarcho-capitalism”? Here I sketch how a system of truly private law could work.

  4. koppl Says:

    Bob,

    Thanks for that reply. I’m not an anarchist, I’m afraid.

    I’ve been hanging out with hard-core libertarians since I began my “Austrian” training in 1980. Thus, I have had some occasion to consider anarcho-capitalism in the past 28 years. I’ve never been persuaded. Perhaps I lack imagination, but I’ve never seen how anarchist views could be even plausible, let alone true.

    I read the piece you link to and the piece of yours *it* links to on private security forces. Let’s say you’re right that a working anarchist system would not degenerate. Okay fine, but how are you going to get there? If we had a magic wand to whisk away the sate, Mafia-like organizations would rush into the vacuum. So you have to tell me how we make a successful transition. That means we need a *design* to get us there. I have a design for improved forensic science. Where is your design for competing security services? The market will not do that for you. It won’t do it for you because the supporting network of formal and informal institutions and cultural norms are absent. We might imagine that such institutions would have emerged if some magic spell had preventing the emergence of the state in the first place. But even if we imagine that, we had no magic spell, we got a state, and we therefore lack the institutional structures required to make anarcho-capitalism function as you imagine. If your basic points are right about the self-sustaining nature of a functional anarcho-capitalism, should you not be busy *designing* the institutional infrastructure of the system? Where is your design, dude? Where is your design?


  5. […] across two cases in which the police won’t use available DNA evidence.  Earlier I blogged about Baltimore, where the police were ignoring DNA evidence.  Now the Chicago Tribune reports, that in Lake […]


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