Oldal 202 [202]
MIRJAN DAMASKA
evidence represents another area in which evidence law purports to interfere with
decision-makers’ native reasoning processes.
Negative legal proof rules, so prominent in the criminal procedure of the
ancien régime, have also not entirely disappeared. These rules, it will be recalled,
are provisions requiring judges to abstain from finding certain facts if they failed
to acquire legally specified evidence. The fact that they have become convinced
of these facts without the prescribed evidence is irrelevant. Consider a few
salient examples. Provisions exist in many jurisdictions exclusively enumerating
acceptable means of proof, or ways in which evidence must be presented in court.
If persuasive information emerges at the trial from means of proof the law does
not recognize, or from evidence presented in an inappropriate manner, judges
are not allowed to use it, no matter how important it may appear to them in
ferreting out the truth. Or consider that in some jurisdictions certain facts cannot
be established without expert witnesses. Appellate court may even deny judges
the power to substitute the expert’s opinion by their own, so that they are left
with the option of either accepting that expert’s opinion, or appointing another
expert in the hope of obtaining an opinion corresponding to their own.° Surviving
are also legal rules requiring confirmation, or corroboration, of reputedly weak
evidence. A relatively recent example is the provision that a conviction cannot be
based solely on hearsay testimony: that the judge may be persuaded of a person’s
guilt by a single hearsay witness makes no difference. It is true that rules of this
genre are disliked, and that their number is dwindling not only in continental
European criminal procedure, but also in Anglo-American justice systems.
Responsible for their present unpopularity is that they are based on an abstract ex
ante determination of probative value, so that they can be over-inclusive and erect
obstacles to the accuracy of verdicts in particular cases. Would it not be prudent,
one might ask nevertheless, to welcome some well selected rules prohibiting
conviction on presumptively weak evidence without legally specified confirmation?
Police confessions, erroneous eyewitness identifications and information supplied
by jailhouse informants come readily to mind. Be this as it may, the opinion now
prevails that the danger of presumptively weak evidence is usually not serious
enough to outweigh the possible increase in unjustified acquittals which could
result from the absence of legally required corroboration. But when all that has
been said so far is taken into consideration, the conclusion is still warranted,
despite this antipathy toward corroboration rules, that free evaluation of evidence
has a considerably more limited reach than is often proclaimed.’
6 This was the position of the German Supreme Court in the middle of the past century. See
Gerhard Walter, Freie Beweiswürdigung, Tübingen, Mohr Siebeck, 1979, 99.
An exception is countries which still cling to jury trials. The juror’s freedom from legal
constraints is especially pronounced in Anglo-American jurisdictions where criminal juries
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