Here are some possibilities, depending on the context and what you want to emphasize:
* First responders: This is a common term used to refer to any group of people who respond to emergencies, including police, paramedics, firefighters, etc.
* Emergency services: This is a broader term that encompasses all organizations involved in providing emergency services, not just police and paramedics.
* The emergency team: This could be used if you're referring to a specific group of police and paramedics working together on a particular incident.
* A contingent of law enforcement and medical personnel: This is a more formal and specific way to describe a group of police and paramedics.
Ultimately, the best collective noun to use will depend on the specific situation and the desired level of formality.