Abstract

Establishing common ground in police investigative interviews is essential in preventing misperceptions and miscommunications, to enable a witness’s best evidence to be collected. However eliciting a consistent account of an allegation from individuals with an Intellectual Disability (ID) is dependent on the skill of the interviewing police officer and the communicative competence of a witness with ID. Acknowledging the specialist nature of this process, the Youth Justice and Criminal Evidence Act in England and Wales allows trained intermediaries to facilitate communication between vulnerable individuals in legal settings such as forensic interviews. Intermediaries i.e., communication specialists, often recruit legally permitted low technology communication aids such as line drawings to facilitate interviews. Typically, common ground is established through shared attention and talk but this article uses multimodality Conversation Analysis to analyse the manner in which common ground in intermediary-mediated police interviews is established in other ways, i.e., firstly, through recruiting and using low technology communication aids in real interviews, and secondly through the embodied physical actions associated with manipulating those aids. Line drawings are examined here, enabling the answers given by witnesses with an ID to be semantically aligned with the questions being asked by the interviewing officers, by establishing common ground. Aids are shown to bypass documented difficulties with attention and staying on topic that individuals with ID typically experience, thus enabling them to verbally provide investigation-relevant evidence.