The present study is devoted to the introduction of biometric identification systems in law enforcement. The author pays special attention to the phenomenon of computer handwriting, examining in detail the constitutional and legal aspects of the use of knowledge about it. For this purpose a wide methodological apparatus is used: comparative-legal method, method of analogy, deduction, method of modelling and others. The Russian practice and potential for further development are compared with the experience of foreign countries both in the regulation of general issues of biometric personal data and in situations of legal regulation of computer handwriting data. The author investigates how to simultaneously solve the problems of detection and investigation of offences in which printed texts act as evidentiary materials, and at the same time preserve human rights to privacy, personal and family secrecy, anonymity on the Internet. It is noted that computer handwriting is a rather young phenomenon for legal science; there is still no in-depth study of it from the perspective of this field of knowledge. This paper is only a beginning in understanding the topic under consideration. It raises basic questions: whether it is permissible to use knowledge about computer handwriting, how it should be protected and where it should be stored, whether it is necessary to limit the existing commercial interest in its use. As a result, the author comes to the following conclusions: it is permissible and necessary to collect information on computer handwriting, as this will reduce infringements on the natural rights of man and citizen. For such collection it is necessary to use a centralised state system in which all the requirements for the security of critical information infrastructure are implemented. However, before such a system is put into operation, it is necessary to support commercial companies in relevant developments and oblige them to provide information about users' computer handwriting at the request of authorised persons.