In an illustrative embodiment, systems and methods for verifying safety compliance of a worker positioned on a building structure utilize a motion detector module (MDM) for attaching to a wearable safety harness, where the harness has a lifeline attachment feature for connecting the safety harness to a lifeline anchored to the building structure. The MDM may include a motion sensor for detecting movement of the worker and processing circuitry for detecting, from signals provided by the motion sensor, significant movement indicative of the safety harness being properly worn by the worker and/or proper attachment of the safety harness to a lifeline, and translating the significant movements into compliance information. The MDM may include a proximate sensor for detecting contact between the attachment feature on the harness and a fastener on the lifeline for verifying the compliance information.