Social Networking, Date Mining, and Criminal Investigation

I have been wondering about the applications of social networking and data mining to the investigation of crimes on the local level. I think a lot of the drug trade takes place over cell phones, and the records of cell phone calls can be subpoenaed. I would guess that the networks involved are strongly hierarchical, with the final sale of the drug to the consumer often being done as the result of a phone call, and that "retail" dealer in turn buying his supplies via phone calls. I suppose that volume dealers sell to many "retail" dealers, and in turn buy from dealers who control even larger volumes. This would seem to be a structure that would be natural for data mining of phone records.

Gangs of young men might also be studied using similar approaches. I suppose that these young men not only use cell phones but also use social networking sites. They must sometimes use the phone in the process of conspiring to commit a crime, and thus making their phone records available to the police via subpeonas. Social network analysis should be able with data mined from phone records and social networking sites to implicate other members in the gangs, and even to identify the gang leadership and contacts among local gangs.

The techniques have been described as developed by intelligence services for the study of international terrorist organizations. I wonder, however, whether they are being used sufficiently widely by local police. The skills involved in doing the mining and analysis should be widely available in colleges and universities, but we might not hear much about them. They are likely to be more important as tools of investigation rather than as proofs of criminal activity. Moreover, they are tools that would be more effective if not widely appreciated by their subjects.