A more thorough explanation:

Gregg v. Georgia is a landmark case in the United States Supreme Court that dealt with the constitutionality of the death penalty for murder. The court held that the death penalty was not inherently cruel and unusual punishment, as long as it was imposed in a manner that was consistent with evolving standards of decency and proportionality.

The court also ruled that the character of the defendant must be taken into account when deciding whether to impose the death penalty, to ensure that the punishment is not disproportionate to the crime. In making this determination, the court considered factors such as whether the murder was committed during the commission of other capital felonies, whether the defendant committed the murder for financial gain, and whether the murder was particularly heinous or depraved.

For example, in the case of Gregg v. Georgia, the defendant was convicted of murdering two men during the course of an armed robbery. The court found that the murder was committed for financial gain, and that it was particularly heinous and depraved, as evidenced by the fact that the defendant shot one of the victims in the back as he was trying to flee. Based on these factors, the court concluded that the death penalty was an appropriate punishment for the defendant's crimes.