“The sole evidence of a handwriting expert is not normally sufficient for recording a definite finding about the writing being of a certain person or not. A Court is competent to compare the disputed writing of a person with others which are admitted or proved to be his writings. It may not be safe for a Court to record a finding about a person’s writing in a certain document merely on the basis of expert comparison, but a Court can itself compare the writings in order to appreciate properly the other evidence produced before it in that regard.
It is not essential that the handwriting expert must be examined in a case to prove or disprove the disputed writing. It is opinion evidence and it can rarely, if ever, take the place of substantive evidence. Before acting on such evidence, it is usual to see if it is corroborated either by clear, direct evidence or by circumstantial evidence. Uncorroborated evidence of a handwriting expert is an extremely weak type of evidence and the same should not be relied upon either for the conviction or for acquittal. The Courts, should, therefore, be wary to give too much weight to the evidence of a handwriting expert.”
– Hon’ble Justice R.K. Agrawal, S.P.S. Rathore v. CBI, [Criminal Appeal No. 2126 of 2010].