Our job is to defend.
It is emphatically not to seek justice unless justice is defined as “trying to get even guilty clients off,” which is a weirdly unlikely definition of the term.
Oh, I don’t know how weird and unlikely it is. Blackstone wrote:
As to the end, or final cause of human punishments. This is not by way of atonement or expiation for the crime committed; for that must be left to the just determination of the supreme being: but as a precaution against future offenses of the same kind.
If the prosecutor’s job is to “seek justice,” it is to seek punishment of the offender as a precaution against future offenses of the same kind. The criminal defense lawyer qua criminal defense lawyer, on the other hand, reasonably doubts that punishing his client will prevent future offenses, regardless of whether or not his client is “guilty.” Indeed, the job of the criminal defense lawyer is to prevent the very specific and definite “offense” which the prosecutor intends to inflict on his client in the immediate future. The job of the criminal defense lawyer is in this respect quite similar to, albeit more direct than, the job of the prosecutor: It is to prevent offenses, or, in other words, to seek justice.
Only if “justice” is equated with “atonement or expiation” does it become weird to say that the criminal defense lawyer seeks justice.
Coincidentally, I happened to watch an episode of Law & Order the other day titled “Justice,” in which former prosecutor Jamie Ross reported herself to the attorney Disciplinary Committee because, while representing a man whom she learned through her representation to be guilty of a murder that another man was on trial for, she gave an anonymous tip on the eve of trial to the deputy who was prosecuting the other man that, if followed through on, would have demonstrated his innocence. (The tip didn’t directly implicate Ross’ client, though it was likely to indirectly implicate him.) The deputy ignored the tip, and was made a judge shortly after the innocent man was sent to death row. Jack McCoy tried to prosecute the judge for attempted murder, but the case was dismissed. Ross was eventually exonerated by the Disciplinary Committee.
See Rule 1.6 of the Indiana Rules of Professional Conduct:
(a) A lawyer shall not reveal information relating to representation of a client unless the client gives informed consent, the disclosure is impliedly authorized in order to carry out the representation or the disclosure is permitted by paragraph (b).
(b) A lawyer may reveal information relating to the representation of a client to the extent the lawyer reasonably believes necessary:
. . .