Maps made by authority of law and filed in the proper office are public documents, and when coming from their legal custodian, and duly certified by him as required by law, are receivable in evidence.6

Unofficial maps, showing the place and scene of a crime, when proved to be accurate representations thereof, may be used in connection with the testimony of witnesses in a criminal case.7 This is for the purpose of better enabling the court and jury to understand the case, by having thus pictorially explained and presented to them the streets, houses, and other surroundings and circumstances connected with the crime, and so that the testimony as introduced may be more easily understood.

It is common practice in the courts to receive in evidence private or unofficial maps, diagrams, models, or sketches, made by the parties themselves for their own private use and convenience, which are shown to be correct representations of places and objects and things which cannot otherwise be as conveniently shown or described by witnesses, as legitimate aids to courts and juries. The correctness or accuracy of such maps or charts need not be shown by the person making them, but any person having knowledge of their accuracy may certify as to their correctness as representations of the locality or objects sought to be shown thereby.8

In Lake Street Elevated Railroad Co. vs. Burgess, 200 111., 631, plaintiff offered in evidence a pencil diagram or sketch purporting to show the rear end of the front or motor car, the front end of the adjoining car, and the platform and opening into which plaintiff claims to have fallen, and also the station platform. There was no writing on the sketch except the words indicating the points of the compass, and the figure "18" in the space between the motor car and the front end of the platform of the adjoining car, and the characters "2 1/2 ft." in the space of the platform or entrance of the car back of the motor. Defendant's claim agent was placed on the stand by the plaintiff, and this diagram or sketch exhibited to him, and he was asked as to its accuracy, and he replied, as far as he could tell, it seemed to be correct. Afterwards, his attention was drawn more specifically to the sketch, and he stated that the corner of the motor car did not seem to be quite as rounding in the sketch as it was in fact, and that it gave the appearance of greater space in the space where plaintiff claims to have fallen than was really there, and spoke of other minor inaccuracies. Plaintiff then offered the sketch in evidence, and upon objection by defendant's counsel, the court said: "You offer it as a sketch simply to aid the jury in arriving at or understanding their testimony, but not as a correct sketch of the car. It will not be introduced in evidence. You can use it in making your argument, but not to go into the jury room, except there is no better. It may be used, not as a perfect sketch of the car or the location, but as an aid to the jury in understanding the testimony of the witnesses in respect to the cars." The court further said: "Of course, gentlemen, this is not meant as a picture of the car or the location there - I mean of the location; but any lawyer, or anybody, has a right to sit down with a pencil there and make a sketch of any kind that tends to represent the location and the things in controversy, and that goes in simply as an aid to the jury. It is not intended except as an aid to the jury."

6 Polhill vs. Brown, 84 Ga., 338. 7 People vs. Phelan, 123 Cal, 551.

8 17 Cyc, 412-413.