Photographs are valuable pieces of evidence in local authority prosecutions but officers should be careful how they are presented. Julie Barratt reveals all A picture paints a thousand words, so the song goes, and that, presumably, is why the practice of exhibiting photographs taken at the scene of the crime is so popular- it can negate the need for thousands of words.

Exhibiting photographs is now such a commonplace practice that the reasons for doing so are sometimes lost. The purpose of giving evidence is to explain to the court what the witness saw. In some cases this is simple - if car A ran into the back of car B, there is not a great deal to say. If, however, an EHP goes into a catering kitchen and finds a scene of filth and devastation, it will take more than a couple of succinctly written paragraphs to paint a picture in the mind of the court of what has unfolded before him or her.

In such circumstances, a series of photographs is priceless as they do clearly show the scene and negate the need for words. There is no need to give evidence to the effect that the cooker was greasy if the picture shows grease on the cooker. Neither is it necessary to say that the refrigerator had not been cleaned if the photograph shows a refrigerator that more closely resembles a polar ice cap than a piece of catering equipment.

Given the undoubted value of photographs, and the fact that they can say so much, why do so many prosecutors feel the need to over egg the pudding? Too often, prosecutors feel the need to describe in prose what the photograph shows, and doing so can be enough to allow the defence to object to the photograph and may result in it being excluded from evidence.

The legal maxim that applies in such cases is res ipsa loquitur - the thing speaks for itself. Where a photograph is exhibited, it must be allowed to speak for itself - that is, the prosecutor should make no subjective comment about what is shown in the photograph. Use of pejorative words is enough to have the photograph excluded from the evidence in the case. The rules about prejudice and probity apply, and since the description of what is clearly shown is both excessive and highly prejudicial, it is right that the photograph should not go before the tribunal of fact, which should be left to consider only the testimony of witnesses. Where considerable reliance has been placed on the photographic evidence, this may cause real problems.

By way of example, where reference is made in a witness statement to a locked fire escape, it is proper to say in the statement words such as, "I inspected the fire door and found it to be padlocked". This is fact. It may be considered that there is some benefit to be gained by showing a photograph of the locked door. Maybe the chain and padlock are sufficient to tether an elephant and seeing this will tell the court something about how realistic it would be to expect a person of normal strength to be able to pull the chain off in a fire. All that is required is a copy of the photograph, exhibited without comment. It is acceptable to say something along the lines of "a photograph of the fire door is exhibited as JB1". No objection can be taken, as no comment has been made as to what the photograph shows. Prosecutors run into trouble when they introduce photographs and comments such as, "exhibit JB1 shows the heavy chain and padlock on the fire door, effectively precluding escape."

Comments such as that shown encroach on the function of the court - the role of the witness is to give evidence as to what was seen or heard, the court makes decisions of fact.

It must be remembered that a good series of photographs can be very damaging to the defence - it is hard to argue that conditions in a filthy kitchen are a blip in an otherwise spotless catering career when the photographs show filth and grime dating back to prehistoric times. Consequently, there is much to be gained by a defence lawyer who can successful apply to have photographic evidence excluded. The loss of such photographs can be equally as damaging to a prosecutor who seeks to rely on the evidence they show rather than hours of oral testimony, so the stakes are high.

It is vital to let the photograph (or video footage) speak for itself, invariably it is more eloquent than the most practised testimony, and cannot be cross-examined. The rule is "simply exhibit the photograph, and exhibit the photograph simply".

Julie Barratt is director of CIEH Wales