Third generation family-owned company offering home security systems Denver burglar alarms, video surveillance and more. At A1 Security, we pride ourselves on giving people peace of mind. Thanks to our state-of-the-art security systems, you can feel safe and secure. We’re a company that you can trust, and not just because we stand by our security systems. We are a third generation, family-owned, local company that is proud of our local service. Most of our monitoring is done right here in Colorado. We understand the value of building relationships over time and strive to provide the highest level of support, expertise, and service. Let us make your life safer and easier.