Answer:
First Responder
Explanation:
The first person that arrives at the crime scene is known as first responder. A first responder is a trained personnel that responds or arrives first at the crime scene. The duty of a first responder is to protect the people and the crime scene and also to regulate the changes that affected the crime scene.
The mood is unsettling and suspenseful. The words "unfamiliar, concerned, unusually, and heavy" help set the mood to this.