"The possible implementation of the death penalty in domestic proceedings would also create a grievous and irremediable consequence for Mr. Gadhafi, and completely undermine the ability of the Appeals Chamber to render a determination on the appeal," Jones wrote to the court.
Libyan prosecutors said in June that Seif al-Islam, Gadhafi-era spy chief Abdullah al-Senoussi who also is wanted by the ICC and ex-premier al-Baghdadi al-Mahmoudi, along with ex-spokesman Milad Daman, will be tried in August for crimes committed during Gadhafi's 42-year rule and the eight-month civil war that deposed him.
In The Hague, Seif al-Islam is charged with murder and persecution of civilians during the early days of the popular 2011 rebellion that eventually toppled his father. If convicted he would face a maximum sentence of life imprisonment at the Hague court, which does not have the death penalty.
Gadhafi was also charged, but the case was dropped after he was captured and killed by rebels.