The use of data acquisition and fusion techniques allow to generate event graphs in support of criminal investigations. In this paper, an anonymized real case study will be presented to identify undue transactions through graph analysis. All the steps of an investigation protocol are illustrated by describing how the tools adopted in this paper allow to semi-automatically analyze huge amounts of data coming from different nature, identifying suspicious transactions with high precision.

Events happening at defined moments in time and involving specific entities from a social or physical system can be organized in networks or graphs. The study of such event graphs may reveal causal relations between subsequent events or compound events that we define as “typed events”. Moreover, characteristic sequences of events or patterns can arise in consequence of phenomena affecting the system. Methods to build the event graph and to search for the typed events and their significance are described in detail. An embedding strategy to encode typed events in low dimensional vectors is defined, and both supervised and unsupervised learning is applied to search for meaningful patterns. Experiments have been conducted using data from a real investigation and some synthetic data.