Thomas Cohen, at the NIJ Bureau of Justice Statistics, has published an interesting study on who is most effective at criminal defense.

Bottom line, from the abstract:

Specifically, this paper examines whether there are differences between defense counsel type and the adjudication and sentencing phases of criminal case processing. Results show that private attorneys and public defenders secure similar adjudication and sentencing outcomes for their clients. Defendants with assigned counsel, however, receive less favorable outcomes compared to their counterparts with public defenders.

A multi-variate aakysus was included:

Other independent variables include extra-legal and legal covariates measuring defendant demographics, most serious arrest or conviction charges, criminal justice status and history, monetary bond amounts, case processing time, and type of conviction.

With the multi-variate analysis:

According to the probit models, defendants with assigned counsel were significantly more likely to be convicted and sentenced to prison, net of controls, compared to defendants represented by public defenders. For example, the Z-scores measuring the likelihood of conviction and state imprisonment for defendants with assigned counsel were .232 and .305 higher, respectively, than for defendants with public defenders. The only outcome in which assigned counsel garnered similar results to public defenders was for incarceration. Defendants represented by assigned counsel were just as likely to receive some form of incarceration as defendants with public defenders. Despite similarities in incarceration outcomes, the combined models provide evidence that defendants represented by assigned counsel received significantly worse outcomes in terms of being convicted and sentenced to prison compared to their counterparts who were represented by public defenders.

The author is cautious however.  From the text:

The inability to account for all factors associated with felony case processing outcomes opens the possibility of selection biases explaining some of the differences between assigned counsel and public defenders. For example, many SCPS jurisdictions employ both public defenders and assigned counsel to represent indigent defendants and in these counties, it is possible that the public defenders are able to select cases where they are more likely to prevail or produce outcomes entailing less severe punishments for their clients. In these jurisdictions, a selection process where assigned counsel are provided the worst cases in terms of conviction and punishment probability, rather than inferior legal advocacy, could explain why public defenders produce better outcomes for their clients. Selection bias could be especially problematic in jurisdictions where heavy caseloads necessitate the utilization of assigned counsel as a means of alleviating public defender workloads. Unless random assignment is applied, public defenders could offload their less favorable cases into the assigned counsel system.

Does this mean that a mixed model using private lawyers for some of a “civil Gideon” or legal aid caseload would result in worse outcomes?  Maybe, maybe not.

Public defenders are a very special case, appearing often in a very major part of the cases in a system, developing both a deailed knowledge of the system, and the personal relationships that are often key to good outcomes.  This is far less the case with legal aid models.

On the other hand, the salaried model allows for far closer supervision than the assigned counsel model, and that should result at least in a lower floor in practice skills.  (Although it must be acknowledged that such supervision and skill development varies hugely within both public defender and legal aid models.)

So, as so often, the conclusion is that more research is needed.  But this data is certainly something that we must keep in mind.