Eath penalty between the U.S and other countries

Discuss the death penalty from the perspective of why some states in the U.S. utilize this form of punishment, vs. why some other countries in the world do not.

Use at least 2 other professional, scholarly sources which may be books or perodicals. Only use two internet sites as references.

Direct quotes should not be used. one book which should be used is

Schmalleger Corrections in the 21st Century, 4th Edition.
I cannot provide the book at this time.