The use of technology within the home environment has been established as an acceptable means to support independent living for elderly and disabled people. An area of particular interest within this domain relates to monitoring of Activities of Daily Living for those persons with a form of cognitive decline. In this area, specific tasks undertaken by the persons in the context of their normal day-to-day lives reveal a wealth of information to be used to customize their environment to improve their living experience. In our current work we investigate the development of models which can be used to represent, classify and monitor basic human behaviors and support observation and control of activities of daily living. In particular, in this paper we focus on the problem of automated recognition of sequences of events that may indicate critical conditions and unexpected behaviors requiring intervention and attention from caregivers. Our work is based on a formal framework developed with temporal logic used for the specification of critical sequences of patterns and a behavior checking engine for automated recognition. In addition we have also developed an approach to provide a means of interaction with user. A visual formalism for the specification of Linear Temporal Logic expressions reduces the barrier of technical complexity enabling the involvement of experts in the domain of healthcare services to interact with the system.