For a long-lived metastable system, the decay of the survival probability is typically exponential. However, deviations are known to exist at short times (the quantum Zeno effect) and at long times (algebraic tails in classical hydrodynamic systems). Deviations are also predicted for quantum systems at late times, but there is only one reported observation [1], of which we are skeptical. In this thesis, we study issues pertaining to the detectability of this late-time effect. We focus on three physical models, namely a specific tunneling model—the well known Winter [2] problem, a generic tunneling model, and a radiating atom model and consider explicit constructions of the decay products' wave functions. We then build a simple non-invasive model for time-resolved spectroscopy and examine the probability of detecting the decay products. We also study the effects of a non-trivial environment on the late-time region of the survival probability for a tunneling particle. We model the particle in two ways and find similar results suggesting that the late-time behavior is not dependent on a particular potential, but rather is more general. Lastly, in contrast to previous studies, we observe a continuous range in the exponent governing the algebraic decay regime.