This is due to a variety of reasons. The data center that houses all of the technology that runs government services is a 24/7 facility, with all of the battery and generator backup required for power, and two fiber internet connections, allowing the RTCC to stay up and running 24/7.
A RTCC is heavily dependent on technology, and locating it near all of the experts within the IT department allows technology issues and integrations to be resolved quickly and cost effectively.
Furthermore, the RTCC division is an unclassified division, with policies and procedures that match an evidence room. This both allows the IT department to deal with personnel problems quickly and hire more quickly than typical Civil Service or HR processes allow.
Finally, the primary mission of the RTCC is to support public safety, but video evidence and surveillance is used across many departments and is useful in many more situations – from natural disasters to weather events like our recent deep freeze, and more.