A criminal Investigator performs one of the most important responsibilities in the defense squad. He should attain accumulative training that will enable him to identify or recognize any oncoming error. In this way, it will help them implement all their expertise procedure in the processes of solving the errors that may occur during the investigation period. They should also recognize the standard, such that, they should talk to the witnesses, review and verify all the evidence which may be verbally, physically or in video form which in turn may be used in the prosecution process. On the other hand, they should interview the identified witnesses such that they may know the current or previous talk.
The criminal investigator should review all the statements so as to determine the useful and to know if they should be defined further. It is their duty to know whether to sue the evidence at the time of interview or not, for example, the videotapes, recorded tape statements or any other evidence. They also must have enough self-confidence when conducting investigatory duties and be able to interpret relevant policies where need be.
For the surveillance, they are also known as the security officers, patrol and inspect property against theft or fires. They use radio and telephone in communication through the request of backup from the police, firemen or medical department in the time of emergency during the investigation period. They also interview witnesses and gather report that may be useful in the law courts. They work specifically on the assigned geographical zone and they can also detain criminal violators or any other crime in the line of duty. The rear work with the undercover detectives to prevent from occurring before the arrival of police.
To both surveillance and the criminal investigator must show proper judgment and common sense in their line of duty and to be able to take charge in areas of emergency.