1. A computer-implemented method for detecting defects on a wafer, comprising: acquiring information for a target on a wafer, wherein the target comprises a pattern of interest formed on the wafer and a known defect of interest having a location that is known and unique relative to a location of the pattern of interest, and wherein the information comprises an image of the target on the wafer acquired by imaging the target on the wafer, the location of the pattern of interest on the wafer, and the location of the known defect of interest relative to the pattern of interest; searching for target candidates on the wafer or on another wafer, wherein the target candidates comprise the pattern of interest; and detecting the known defect of interest in the target candidates by identifying potential defect of interest locations in images of the target candidates and applying one or more detection parameters to images of the potential defect of interest locations, wherein said detecting is performed using a computer system.