In every crime, conviction of criminal depends upon the appreciation of evidence by courts of law. But the collection of evidence is done by law enforcement agencies, preserved and presented as per law and process defined by law. Digital Evidence is now prevalent be it cyber crime or any other crime, like data theft, privacy compromise, electronic frauds or IPR theft. A need was felt to provide SOP for investigation of digital devices and systems and collection, preservation and presentation of digital evidence. Our book is the culmination of this effort of one year.