Proportionality Before Proof

This Version 1.0 preprint develops the concept of investigative privacy surface: the field of private, relational, communicative, contextual, and third-party information that becomes available or necessary for criminal-justice inspection when cumulative and relational allegations are sorted into possible criminal liability. The article argues that offences concerning coercive control, psychological violence, stalking, digital monitoring, grooming, online harassment, economic control, and related forms of relational harm create a distinctive proportionality problem before guilt has been established. Investigation may require reconstruction of relational ecology through messages, financial arrangements, behavioural changes, digital traces, professional records, family context, and third-party observations. The article therefore introduces two further concepts: collateral privacy burden, referring to the costs borne by third parties whose lives become evidentially relevant, and pre-liability proportionality, referring to the requirement that such investigative exposure be justified under conditions of legal uncertainty. The paper connects criminalisation theory, criminal procedure, evidence, and privacy theory. It offers a preliminary typology of investigative privacy surfaces, a five-question pre-liability proportionality test, and implications for mechanism-sensitive offence drafting, staged investigation, third-party filtering, and the preservation of non-penal support pathways. Psychological violence and coercive control are used as a strategic illustration. The argument does not oppose the criminalisation of serious relational harm. It argues that criminalisation is incomplete unless lawmakers and criminal-justice institutions also assess what private and third-party material must be exposed in order to apply the offence proportionately before proof. Status: Zenodo preprint, Version 1.0. The manuscript has not undergone peer review.