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Through-wall human presence and vital-sign detection is an important requirement in military surveillance, rescue operations, and intelligent security systems where direct visual monitoring is not possible. This work presents a dual-mode millimeter-wave radar-based system for detecting human motion and breathing activity behind non-metallic barriers. The proposed system integrates a motion and position detection sensor with a breathing and vital-sign detection sensor to identify both moving and stationary human targets. Radar data acquired through the sensing modules are processed using an embedded microcontroller, where noise filtering, clutter removal, micro-motion extraction, and data fusion are performed. The motion detection module identifies target movement and position, while the vital-sign module analyzes small chest movements caused by respiration. A decision logic unit combines both outputs to confirm human presence and reduce false detection caused by static objects or environmental interference. The final results are displayed through an LCD interface, transmitted wirelessly for remote monitoring, and indicated using a buzzer alert. The proposed system provides a compact, low-power, non-contact, and privacy-preserving solution for real-time through-wall monitoring. It is suitable for applications such as defense surveillance, intruder detection, disaster victim localization, andsmart building security.