A method for detecting a weapon, the method comprising: emitting a radiofrequency signal stream (16, 44, 88) into a region of interest (40, 60, 80); receiving a scattered signal stream from the region of interest (40, 60, 80), the scattered signal stream generated in the region of interest (40, 60, 80) from the radiofrequency signal stream when a target (18, 46, 64, 86) is at least partially within the region of interest (40, 60, 80); identifying a late time response portion of the scattered signal stream and an early time response portion of the scattered signal stream; identifying a plurality of resonant signal components from the late time response portion of the scattered signal stream as a plurality of decaying sinusoids; generating a plurality of preprocessed resonant signal components by removing at least one decaying sinusoid from the plurality of resonant signal components, the at least one decaying sinusoid corresponding to stored environmental signal components for the region of interest (40, 60, 80); determining a target assessment from the plurality of preprocessed resonant signal components and the early time response portion of the scattered signal stream using a statistical model that is based on resonant signals and early-time responses associated with the weapon, wherein the statistical model is generated using a training database having a first dataset with a first plurality of decaying sinusoid signal components and early time responses associated with the weapon and a second dataset with a second plurality of decaying sinusoid signal components and early time responses associated with a generic target when the weapon is not present on the generic target; and triggering a target response if the target assessment indicates the weapon is detected on the target (18, 46, 64, 86). emitting a radiofrequency signal stream (16, 44, 88) into a region of interest (40, 60, 80); receiving a scattered signal stream from the region of interest (40, 60, 80), the scattered signal stream generated in the region of interest (40, 60, 80) from the radiofrequency signal stream when a target (18, 46, 64, 86) is at least partially within the region of interest (40, 60, 80); identifying a late time response portion of the scattered signal stream and an early time response portion of the scattered signal stream; identifying a plurality of resonant signal components from the late time response portion of the scattered signal stream as a plurality of decaying sinusoids; generating a plurality of preprocessed resonant signal components by removing at least one decaying sinusoid from the plurality of resonant signal components, the at least one decaying sinusoid corresponding to stored environmental signal components for the region of interest (40, 60, 80); determining a target assessment from the plurality of preprocessed resonant signal components and the early time response portion of the scattered signal stream using a statistical model that is based on resonant signals and early-time responses associated with the weapon, wherein the statistical model is generated using a training database having a first dataset with a first plurality of decaying sinusoid signal components and early time responses associated with the weapon and a second dataset with a second plurality of decaying sinusoid signal components and early time responses associated with a generic target when the weapon is not present on the generic target; and triggering a target response if the target assessment indicates the weapon is detected on the target (18, 46, 64, 86).