The Major Case Response Team is the group of professionals tasked with processing crime scenes and collecting evidence. MCRTs collect fingerprints and biological trace, impression, and other evidence, as well as photograph the scene and make sketches of important details. They are essential to NCIS' performance of its crime fighting and law enforcement duties.  

The typical MCRT consists of 8-10 people and is led by a designated forensic specialist with advanced training, often including a Master's Degree in Forensic Science. Individual team members have enhanced training in specialties such as crime scene management, photography, scene documentation, latent fingerprint processing, biological and trace evidence detection and collection, and the proper documentation of impression evidence.

There are 27 deployable MCRTs stationed around the world. They respond to death scenes and assist with the investigation of many other high-impact crimes, including sexual and/or aggravated assaults, acts of arson and wrongful destruction, and thefts. MCRT members also help NCIS case agents (Special Agents assigned to lead investigations in the field) by conducting complex searches, attending autopsies, and performing other duties related to their areas of specialized training. 

The specialized team approach is key to NCIS' ability to quickly dispatch people with the necessary skills to detect, preserve, and interpret important details at crime scenes. Case agents especially recognize the value of the MCRT; with a dedicated team of specialists on the scene, they are able to focus on pursuing leads and other time-sensitive aspects of the investigation.