Pertaining to the seizure of digital devices, there is some misunderstanding concerning what “executing the warrant within ten days” actually means. Many investigators (and some prosecutors) have interpreted this to also mean that the forensic analysis of the digital devices must be completed within ten days after they are seized. This is not a correct interpretation. There is no requirement or mention in the Federal Rules of Criminal Procedure regarding any time limits for the forensic examination of evidence.1 Investigators only have to execute (serve) the warrant within ten days after it is issued to avoid it becoming “stale.”2
Concerning computers (and other digital devices or digital media), there are different interpretations as to whether another search warrant is necessary to conduct further analysis after seizure. Normally, when a computer is going to be seized, the investigator would clearly explain in the supporting affidavit that after its seizure and removal from the scene, it is going to be searched for evidence. Often, investigators will detail what types of computer files they are going to be looking for so as not to run afoul of the Fourth Amendment which requires that every warrant must “particularly describ[e]…the…things to be seized.”4 This requirement restricts and prevents law enforcement from executing a general warrant to search for evidence of a crime.
When investigators initially seize a computer without a warrant, they usually obtain one prior to the forensic examiner beginning his/her analysis. The warrant would indicate the scope of the search, specifically listing the potentially incriminating files or data that the computer’s hard drive may contain. However, since the computer is already in police custody, this raises the interesting question as to how to maintain the legal requirements of serving a warrant. The warrant would have to be served on the computer itself. As strange as this may sound, a number of investigators have indicated to me that this does occasionally occur in their jurisdictions, and I have actually witnessed this practice on several occasions.
From: Search Warrants and Digital Evidence by John J. Barbara