When you ask Douglas Starr, co-director of the Knight Center for Science Journalism, what difficulties he faces in writing his new non-fiction book about the early days of criminal forensics, he answers his main sources are all dead. “I wish I could pick up the phone and talk to them,” he says.

As far as I’m concerned, I wouldn’t bring all of them back to life!

I’m Professor Starr’s research assistant and since September 2006, I’ve been reading and sorting archives he brought back from France.

Starr’s book is based on a famous case of a serial killer who ripped and raped his victims in the France of the 1890s. Starr plans to use the case as the thread for his book. The three main characters, Joseph Vacher, the killer, Emile Fourquet, the prosecutor who tricked Vacher into confession, and Alexandre Lacassagne, a doctor who used scientific techniques to solve the case, will evolve in an atmosphere of vagabondage, murders and intellectual revolution. The case was famous because the investigators learned about the crimes, piece by piece after they arrested Vacher.

One day of October 2006, I was working late on some witnesses’ testimonies, when I came across a woman’s declaration full of great details about an aggression she was the victim of. Starr had asked me to look for those details that would help him build his characters. So I read it carefully.

The woman was just coming back from selling some oranges. She was pushing a carriage in front of her and arrived near some train tracks. At the time that she was about to cross the tracks she felt herself grabbed from behind without having heard anyone approach. The man lifted her undergarments up to her stomach with his knee. He had opened his trousers. He held her with his right hand and with his left hand he was touching her sexual parts. He told her to hold still. At the same time he took a knife out of his pocket, she left her carriage and the knife rolled onto the ground. The aggressor was surprised and at that moment briefly let her go. She jumped and started running to the other side of the tracks where she grabbed some rocks and started throwing them at his face, shouting for help. The attacker began to get frightened when he heard her screaming. He ran away with the speed and agility of a rabbit.

That night, when I went to pick up my laundry in my basement, I couldn’t help checking if someone was following me.

The book won’t only deal with the serial killer case but also with Criminal Science. In those times, there was a great debate between the School of Italy and the School of France. “The Italian doctors would just look at somebody physically and say he was a criminal. Whereas the France scientists would look more at the psychological history of the person,” Starr explains.

Starr is still looking for an important piece that would help him fully understand the killer. “I know a plaster of Vacher’s brain is hidden somewhere in Paris,” he says.

Currently, I’m searching the archives for hints on Lacassagne’s meeting with Vacher at the Prison St Paul while he was evaluating his mental health.

The book, published by Alfred A. Knopf, is due for September 2008. Starr planned to start writing it this September.