One of important medical accomplishments of the past half century is screening to detect breast cancer. Mammography screening, however, cannot find all cancers and it is not a perfect way. Our goal is to develop an automated device, using contrasting mechanical properties of normal and abnormal breast tissue, which can detect the presence of cancer. In this work, gelatin phantoms have been designed to try to reflect the mechanical properties of breast tissue. In order to understand fundamental mechanics of palpation to detect breast cancer, a rigid inclusion was embedded in phantom gel to simulate the lesion. In this work, characterization of phantom gel with an inclusion using indentation is reported. Mechanical indentation is shown to be a good tool to complement a number of existing imaging techniques, and allows one to design and fabricate an automatic way to detect breast cancer.