Smartphones constantly interweave into everyday life, as they accompany individuals in different contexts. Smartphones include a combination of heterogeneous data sources, which can prove essential when combating crime. In this paper we examine potential evidence that may be collected from smartphones. We also examine the available connection channels for evidence transfer during a forensic investigation. We propose a Proactive Smartphone Investigation Scheme that focuses on ad hoc acquisition of smartphone evidence. We also, take into consideration the legal implications of the proposed scheme, as it is essential that the scheme includes prevention mechanisms, so as to protect individuals from misuse by investigators or malicious entities.