forensic

Document examination is a subject which cannot be learned from a single book. The mastery of its requires acquisition of a wide and varied knowledge of specific subjects and application of that knowledge in a practical way to an actual problem.It necessitates long and thoughtful study, exhaustive experimentation and broad practical experience.......

Unfortunately,  it is beyond the compass if certain minds to ever master the subject of document examination. Some people lack the ability not only to observe accurately but to reason correctly. Others may be without the requisite backgrounds education, or be unwilling to pay the price in study and research which true grasp of the subject demands. They may have neither the zeal and enthusiasm so necessary to work, nor the moral courage to boldly and fearlessly follow the facts regardless of where they may lead.....

He must have the ability to convince others that his conclusions are correct. This requires not only technical skills, but is heavily dependent upon human qualities, personality, appearance, honesty, ethical attitude, correct use of language, and background education.