Medical experiments were performed on Jews while detained in the camps. Dr. Mengele is one of the most well-known leaders of these experiments. He mainly worked with twins. Dr. Mengele carried out torturous experiments, with no point to them but to feed his interest of the unknown genetic factors among twins. For example an inmate named Vera Alexander reported that twins were sewn together at the veins to make them siamese through their backs and wrists. Rigorous data was taken from these experiments, and pictures and files can still be found today.