Hi, I'm a developer with more than 30 years of experience. I'm currently retired, but the past 20 years was full-time (in-situ) employed by two international organizations, including the United Nations.
I can develop this application using OpenCV in about 7 days + another 7 days for debugging and fine-tuning. I would need, of course, samples of the videos of your CCTV system, to check for quality and feasibility.
Best regards,
Marco García