In a bid to enhance responses to individuals in mental health crises, Arlington County has implemented the Marcus Alert System. This system aims to coordinate between the 911 call center, regional crisis center, and law enforcement to offer enhanced services to those in need, whether it is related to mental health, substance abuse, or developmental disabilities. The system is also operational in Prince William, Loudoun, and Fairfax counties.

Named after Marcus-David Peters, a Black biology teacher killed by Richmond police in 2018 during a mental health crisis, the Marcus Alert System aims to bridge the gap between the behavioral health and criminal justice systems. A law passed in 2020 required Virginia localities to establish protocols for better responses to mental health calls, resulting in the implementation of this system.

Emergency call takers have received specialized training in mental health and psychotic disorders, as well as crisis de-escalation tactics. This training is crucial in ensuring a compassionate and appropriate response to those experiencing behavioral health crises. By 2028, all cities and towns in Virginia with over 40,000 residents are mandated to have the Marcus Alert System in place to provide equitable access to behavioral health resources for all individuals.