Capital Security Systems.. Capital Security Systems are a leading provider of burglar alarms, CCTV systems and door entry systems for home security and business security in and around London. Quality.. The installation of security systems is carried out by our qualified, approved engineers who with high installation standards, minimise disruption to your home or business. Our security systems comply with current British and European standards. Exeptional Service.. We pride ourselves on our total service from sales to after-care. Our interest does not end with the sale, it is always our aim to build a long term relationship with our customers.