Today’s security climate calls upon CCTV as an integral part of a security plan. Most of the halachic discussions appear to focus on the camera itself as it relates to K’Sevia. However, many Shuls have a security room and security guards are volunteer Shul members trained to detect and report suspicious activity. As such, the cameras are typically connected to a monitor (assuming in a non public location). May a Jewish Volunteer Security member view the monitor to detect any unusual persons or behavior on Shabbos?
ב"ה Shalom As you said, the security climate requires taking these measures. Of course, in each community based on the assessment of local law enforcement and other security agencies, the local Rabbi will decide what is necessary. Once the Rabbi decides these measures are necessary, most of the security measures will come under the category as "pikuach nefesh" of saving lives which is permitted on Shabbat. In regard to your question, the viewers who are doing their job, are not doing anything that desecrates Shabbat, as long as the cameras and monitors are not activated by any person on Shabbat but done automatically, so there is no problem just viewing. Perhaps, some reminders should be placed not to make adjustments on Shabbat and it would be a good idea to make a test run before Shabbat. הנה לא ינום ולא יישן שומר ישראל All the best