The majority of work described in this paper was conducted as part of the Recovering Evidence from Video by fusing Video Evidence Thesaurus and Video MetaData (REVEAL) project, sponsored by the UKs Engineering and Physical Sciences Research Council (EPSRC). REVEAL is concerned with reducing the time-consuming, yet essential, tasks undertaken by UK Police Officers when dealing with terascale collections of video related to crime-scenes. The project is working towards technologies which will archive video that has been annotated automatically based on prior annotations of similar content, enabling rapid access to CCTV archives and providing capabilities for automatic video summarisation. This involves considerations of semantic annotation relating, amongst other things, to content and to temporal reasoning. In this paper, we describe the ontology extraction components of the system in development, and its use in REVEAL for automatically populating a CCTV ontology from analysis of expert transcripts of the video footage.