ON ADMISSIBILITY OF DOCUMENTS, INSTRUMENTS, AND TESTS
"Concentrate on what cannot lie. The evidence." (CSI pilot episode)

    Anything "documentary" is essentially anything that is non-oral at law, but this doesn't mean that a witness can't be involved.  The phrase "documentary evidence" is generally used to describe anything introduced by witnesses, and "real evidence" most generally refers to evidence offered up by witnesses who make its introduction possible. Examples of documentary evidence are:  written instruments; inscriptions, and documents of all kinds (any form of writing or recording, mechanical or electrical).  No documentary evidence can be admitted without meeting both the authentication requirement and best evidence rule.  It is also the case that, at law, the absence of documentary evidence may be considered proof that an event never happened.

    "Real evidence" refers to the introduction of objects which played a role in the crime (such as gun, knife, clothing, or parts of the body), but that is a strict interpretation since many authorities do not distinguish all that sharply between demonstrative and real evidence.  Rules are fairly loose on such things as courtroom demonstrations and experiments (the standards being "substantial similarity" or "similarity of conditions" for relevancy).  There have been various types of real evidence that have been held admissible, and for each type, certain conditions must be met.

     The results of examinations and tests (i.e., laboratory tests) are a type of real evidence.  Standards for admissibility vary widely.  For example: intoxication testing may vary from state to state; courts have wide latitude in ruling on the admissibility of blood comparisons; polygraphs aren't admissible at all in some states; fingerprint comparisons may be heavily scrutinized; etc.  Such evidence is also scientific evidence, or more accurately, "forensic" evidence  -- the kind that researchers have found makes police about three times more likely to clear cases (Klotter & Ingram 2004).

DOCUMENTARY EVIDENCE

    Any form of writing or recording is a document, and regardless of whether it's public or private, it may be admitted into evidence if it meets the same standards as oral testimony (relevancy, competency, and materiality), but in addition, a foundation must be laid for the introduction of documentary evidence.  Meeting the requirements for authentication and the best evidence rule are two tests that relate primarily to documentary evidence.  A writing, by itself, is evidence of nothing, so all documents admitted must have a proven connection to the case, be genuine, and be what they purport to be.  The authentication requirement is usually met by providing preliminary proof of genuineness, authenticity, or identity.  A "proponent" (as they are called) must present foundational evidence that is sufficient to constitute a rational basis for a reasonable juror to conclude that the primary evidence is what its proponent claims it to be.  Sometimes, a stipulation substitutes for a formal authenticity requirement, and additionally, some documents are self-authenticating (when the document becomes, by authority of statute or being an "official" document).  In such cases, the required proof is said to be contained within the document itself.  The use of circumstantial evidence is allowed to authenticate a document. 

    Depending upon the character of a document, different procedures exist.  Official records may even need an attesting certificate (when photocopies are involved).  Ancient documents (where nobody is left alive to verify something) have relaxed rules (and a 20-year period is necessary for something to become an ancient document).  Non-experts are satisfactory for many things (like handwriting), but experts are frequently needed with anything technical or complex in nature (like computer evidence).  Self-authenticating documents include: public documents (under seal or attested to); foreign documents attested to; copies certified by custodians of originals; official publications; newspapers and periodicals; trade inscriptions or labels; documents acknowledged by a notary public; commercial paper; documents cleared by Congress; and certified domestic or foreign records of regularly conducted activity.  Just because something is well-authenticated does not preclude the opposing party from challenging it on grounds that the document is not what it purports to be (and on any other proper evidentiary rule).  Proof of signing is the most common method of authenticating a document, and when/where an original cannot be produced, the (imperfect but practical) best evidence rule is followed.

    The best evidence (for purposes of understanding the best evidence rule) is that which is obtainable under the circumstances of the case to prove any disputed fact.  Clearly, there is a legal preference for the original and most accurate rendition of a document, but sometimes proof of a lower degree (secondary evidence) will be received when nonproduction of the original is properly excused thru no fault of any party.  The best evidence is a qualified substitute or duplicate (duplicates being the more common reference for the phrase "secondary evidence").  The best evidence rule does not matter all that much unless the content is at issue, and to meet the rule, the original must have been: (a) lost or destroyed (not in bad faith); (b) not obtainable; (c) in the possession of an opponent; or (4) no related to the controlling issue.  The purpose of the best evidence rule is to prevent inaccuracy and fraud.  In many cases, the best evidence rule doesn't apply.  In other cases (like with computer searches and seizures), it is widely used.  Further within the interest or spirit of justice (and judicial economy), a number of other admissibility options exist; e.g., summaries of voluminous documents; and reliance upon academic books and treatises. 

REAL EVIDENCE

    Real evidence normally involves that which has always been recognized among the ordinary indicia of a criminal offense and where the practice of identifying it by circumstantial evidence and by the inspection of witnesses and jurors is justified on the basis of immemorial usage and time-honored practices.  Real evidence is also evidence that is addressed directly to the senses (such as sight, hearing, or taste).  That is, it serves as a visual (or sensory) aid for a jury to better understand a witness (and it has probative value -- unlike demonstrative evidence, which possesses no probative value in itself).  Sometimes, the two are combined (into "demonstrative real evidence") when, for example, a medical examiner might use a mannequin in court to display what happens when a weapon impacts the head (and pieces of styrofoam shoot out all over the jury).  This is perhaps not the best example, and it is perhaps better to explain that most real evidence goes to crime scene issues.  That is, most witnesses called upon to corroborate real evidence (items connected to the crime scene) do so by: (a) helping establish a chain or continuity of custody; i.e., "bagging and tagging and marking" crime scene evidence properly enough so that such evidence may be admitted even with slight deficiencies and where a jury is free to give less or more weight to such evidence as it sees fit, the failure to preserve evidence (outside of  bad faith) not ordinarily constituting a denial of due process; (b) helping establish necessity; i.e., necessity going to concerns over the weight of the evidence (if highly probative, better evidence cannot be admitted because it would appeal to the emotional and sympathetic tendencies of a judge or jury, other evidence is admitted for the sake of necessity); and (c) helping establish the relationship of a physical object to the commission of a crime. 

    The most common type of real evidence is presentation of the victim (or photographs thereof) to the jury.  Devices and instruments used in the commission of a crime are also admitted as real evidence.  Clothing and/or other items possessed by the defendant at the time of commission are frequently submitted to the jury for inspection.  Bloodstain evidence generally requires expert collection and evaluation. 

    Every trial has the option to view the crime scene or not (a motion will be granted or denied).  The purpose of a crime scene view is to help the jurors obtain a mental picture of the locality, and the procedures vary.  A common procedure is to not allow the jurors to talk or ask questions.  Other procedures involve whether the presence of the accused is required or not, and how many police officer escorts there are.  Photographs and videotapes are increasingly relied upon by the courts as a more convenient option.  Some courts will allow the introduction of "posed" photographs, but as a general rule, nothing "gruesome or inflammatory" can be admitted.  Forensic art can be admitted, but in most cases will require the testimony of the artist.  No diagrams, maps, or models can be prejudicial.  A foundation must be laid before any photographs, motion pictures, X-rays, or sound recordings can be admitted, and the most basic standard involves whether any probative value outweighs any prejudicial value.    

EXAMINATIONS AND TESTS

    When an out-of-court test or examination is conducted, there are rules for admissibility, mostly involving the testimony of a scientific expert.  The stakes are often high with this type of evidence.  Lab reports can be unequivocal and clear or eliminate some suspects, while providing ironclad proof at the same time.  The most frequent kinds of tests are with bodily fluids of the defendant, and obtaining these fluids is not considered violative of any constitutional rights.  Victim autopsies are also a frequent kind of examination, and medical examiners are only allowed to testify about their anatomical findings, anatomical diagnosis, and cause of death.  Intoxication tests exist with various rules that vary by jurisdiction, and polygraph tests are legal in some places and not in others.  Ballistic experiments may have been carried out.  DNA testing may have been done.  It is up to the individual judge at each trial to take (or not take) judicial notice of whether a certain scientific examination or test is a well-recognized (and one of the surest) methods of identification. 

    Judicial notice takes the place of proof, and is of equal force.  In many ways, it is superior to evidence (since it stands for proof).  Along with presumptions and stipulations, judicial notice makes up one of three (and only three) substitutes for evidence (and these three things are usually re-emphasized to the jury by the judge's closing remarks or jury instructions).  Judicial notice is defined as "the recognition and acceptance of certain facts that are reasonably undisputable that a judge, under the rules of evidentiary procedure, may properly take or act upon without proof" (Klotter & Ingram 2004:98).  The rules governing judicial notice are often categorized as judicial notice of facts and judicial notice of laws.  Judges (not based on their extrajudicial or personal knowledge, but upon "common knowledge") can make judicial notice about the following matters of fact: general knowledge (e.g., the fact that tobacco smoking is dangerous); history (wartime eras); geography (size and distance); nature and science (the laws of gravity or thermodynamics or DNA testing reliability); and abbreviations and symbols (slang or religious markings).  Judges can make judicial notice of the following matters of law:  law of the forum (jurisdiction); federal law; law of sister states; law of foreign countries; municipal ordinances; and administrative regulations.  Increasingly, however, the modern trend is for judges to be cautious, and to hesitate when taking judicial notice of facts and laws, particularly in borderline situations.