The third week of the trial of those suspected of involvement in the November 2015 terrorist attacks in Paris was entirely devoted to police and expert evidence. Much of what we heard and saw was difficult for the families of victims.
In the course of the week's hearings, we listened to crime scene investigators, to the police surgeon who performed the autopsies on those killed, to an explosives expert. None of it was pleasant.
There was also the testimony of the police commissioner, unnamed for security reasons, who went into the Bataclan on his own initiative, armed with a hand gun, in the midst of a terrorist attack by a then-unknown number of men wielding weapons of war.
The policeman's first act was to shoot Samy Amimour as the so-called jihadist was preparing to execute another victim. Amimour's suicide vest exploded, and the two remaining killers realised that they were no longer in control of the situation.
The officer then risked his life repeatedly to drag survivors from the building while the anti-terrorist brigade prepared their final assault.
"Your action saved countless lives," the court president told the witness.
"I did my job," was the simple reply. "You don't become a policeman by chance."
The cowardice of ritual killing
The week came to a close with a harrowing glimpse of the other end of the human spectrum.
Another security-protected anonymous police specialist explained what had been learned from the succession of claims of responsibility for the attacks issued by Islamic State.
The initial message from the terrorist group, on the day after the killings, alerted the Paris authorities to the number of killers involved, and to the possibility that at least one terrorist was still slated to act.
The propaganda effort of the so-called caliphate culminated in a professionally produced 28-minute video in which seven of the soon-to-be Paris attackers address the camera before murdering western hostages, five of the victims being beheaded, two shot in the head.
The contrast could not have been more stark between the bravery of a man doing his duty at the risk of his own life, and the cruel cowardice of those who horribly murdered defenceless innocents.
The trial continues.