Scoping out a case before taking it on is good practice regardless of its size or relative importance, but this becomes even more pertinent when international factors might be involved. These may have an impact on the time it takes to acquire evidence: for example, if you are looking to extract data from a server in another country, or even another state, you will need at least a basic understanding of the requirements necessary to gain access to it, and indeed whether this is even possible in the first place.

It is, of course, impossible to have an in-depth understanding of the various bits of legislation that are relevant to digital forensic investigations around the world. In reality, the best an investigator can do is to verse themselves as fully as possible in the laws of their own local area, and then seek advice when the need arises to work across borders.

Beyond the legislative elements, however, there are also the more mundane aspects of international investigation, such as linguistic analysis. Keyword searches are often where an investigation starts, or at least fall somewhere near the beginning—but if your case spans a multitude of countries, you may well end up at a loss for keywords.

Most of the larger digital forensics solutions, such as EnCase and Nuix Investigator, have multilingual keyword abilities built in, which is a huge help. Some can even scan the evidence you enter for you, and then bring back an analysis of the languages used within the case. You can then use this to form the basis of your investigation and to inform future searches. Slang is still a problem for many though, and criminals are increasingly becoming wise to this. While a thesaurus can bring back a number of synonyms for a given term relating to drug abuse, the exploitation of children, or financial fraud, it may not be able to include all the less formal terms people are using in their discussions.

Progress is being made, however, and much of the air time at digital forensics conferences and research groups is devoted to how we as investigators can increase collaboration and make it easier to investigate global cases.