States with the death penalty have consistently had higher murder rates than states without the death penalty. If the death penalty was acting as a deterrent to murder, one might expect that the gap between these two groups would lessen over a long period of time as states using the death penalty obtained an advantage in reducing murders. However, the gap has grown larger over the past 18 years. In 2007, states with the death penalty had a 42% higher murder rate than states without the death penalty. In 1990, the gap was only 4%.