In some police systems, the detective job role is occupied by the fresh college graduates who take up the job role directly from a civilian life and not being served as a uniformed officer. Some people have an argument the detective is not like normal police officers, as they indulge in a different job role they need to be trained differently from police officers. The opposing argument mainly holds a statement that a detective cannot take up the role as without being serving as a uniformed patrol officer. Because a detective cannot have great commands of standardized police procedures and will find it difficult to indulge in the works of a uniformed personnel.
There are many private investigators and detectives with specialized practical and academic experience and they also work with defense attorneys on special occasions like criminal defense cases and other capital punishments. And other investigators are investigators who investigate as insurance investigators and even on other suspicious claims. Before the declaration of no-fault divorce, there were many private investigators seeking evidence of extramarital affairs and adultery of the spouse in order to establish a evidence that is very strong and would lead to divorce. Despite the negligence of legal necessity for such submission of evidence in any jurisdiction, according to some press reports, gathering pieces of evidence of spouses' and partners' bad behaviors and adultery is one of the most profitable undertakings done by private investigators.