Like a scene from a crime thriller film, a prisoner who faced interrogation over a murder was shot to death inside his French jail by a sniper positioned on a nearby hill.
The suspected gunman, his rifle still warm from the shooting, was later arrested as he tried to flee the scene on a motorbike.
Another inmate, a friend of the dead man, was injured in the attack during which five shots were fired into the exercise yard of the jail at Varces-Grenoble, in southeast France.
It was the first time in France that someone in prison had been killed from outside, French Justice Minister Rachida Dati said.
The murdered prisoner was identified by a French newspaper as Sghair Lamiri, who was born in 1979 and had links to organized crime.
Lamiri was serving an eight-year sentence for robberies committed in 2001 and 2002 and was about to be questioned about a murder case, Dati said.
Ms Dati did not name the suspected gunman, but said he was 58 years old and was in custody.