Abstract: Many theories beyond the Standard Model predict new particles with lifetimes long enough to travel measurable distances before decaying. These long-lived particles (LLPs) often produce unconventional and challenging signatures in the detector. To efficiently capture these signatures, dedicated trigger strategies and innovative use of detector capabilities are employed to enhance the sensitivity of LLP searches. In this seminar, I present results using CMS data from Run 2 and the ongoing Run 3 of the LHC, including a novel approach based on the Muon Detector Shower signature. I conclude with prospects for the High-Luminosity LHC, where upcoming detector and trigger upgrades will enable next-generation LLP searches.