Reign of terror: 10/01/69 - 07/01/76
Motive: Unknown
Crimes: Barbeault was found guilty of two counts of murder, three counts of unlawful killing, sixteen burglaries and a number of other minor offences. However, the following attacks are those attributed to the Shadow Killer:
| Date of crime | Victim | Age | Place | Crime |
| 10 / 01 / 69 | Francoise Lecron | - | Her home, Nogent-sur-Oise | Shot in shoulder |
| 14 / 01 / 69 | Michele Louvet | 17 | Nogent-sur-Oise | Shot in stomach |
| 24 / 01 / 69 | Therese Adam | 49 | Nogent-sur-Oise | Murder |
| 16 / 11 / 69 | Mme Suzanne Merienne | 44 | Nogent-sur Oise | Murder |
| 06 / 02 / 73 | Annick Delisle | 29 | Nogent-Sur-Oise | Murder |
| 29 / 05 / 73 | Eugene Stephan | 25 | Nogent-sur-Oise | Murder |
| 29 / 05 / 73 | Mauricette Van Hyfte | 23 | Nogent-sur-Oise | Murder |
| 08 / 01 / 74 | Josette Routier | 29 | Her flat in Nogent-sur-Oise | Murder |
| 26 / 11 / 75 | Julia Goncalves | 29 | Hebert Park, Nogent-sur-Oise | Murder |
| 07 / 01 / 76 | Francoise Jakubowska | 20 | Villers-Saint-Paul | Murder |
Method: All the victims were shot with a .22 rifle. Several of them were also hit on the head. Josette Routier and Francoise Jakubowska had also been cut on their breasts and stomach.
Sentence: Barbeault received a sentence of life imprisonment for his crimes following his trial in May 1981. In March 1982, his conviction was quashed and a retrial took place on November that year. The verdict was once again guilty. His sentence was reduced to twenty year's imprisonment.
Interesting facts: The Shadow Killer was so named because he shot his first victims from whilst hiding in the shadows of nearby trees. The murder of Suzanne Merienne was different in that the killer came into her house and ordered her and her 19-year-old daughter to leave and walk to wasteland next to the railway. The 19-year-old managed to escape.
During the investigation into the murder of Eugene Stephan and his girlfriend, investigator's found a gun casing by a standpipe in a nearby cemetry. At the time, this was not considered overly helpful, but in fact it became the reason why Barbeault was caught.The investigating officer considered that it had been dropped as the killer went to wash himself. Given that it was the middle of the night, the investigating officer concluded that the killer knew his way about the cemetry as he was a frequent visitor. He collated the names of all those who had cause to visit the cementry (around 2,500) and whittled that down to Barbeault.
On 14th December 1976, the police searched Barbeault's home. In his communal cellar, they found a .22 rifle, a paratrooper's knife, a cosh and some brown oilskins, significant because that was what the killer wore in the murder of Mme Merienne. The rifle was forensically proved to be the same one as had fired the shots from the last two murders.
Barbeault was also a burglar. In 1970, during a burglary already attributed to Barbeault, a .22 Reina rifle was taken. This was forensically proven as being the gun that shot Eugene Stephan, Mauricette Van Hyfte annd Josette Routier. There was another weapon involved in the murders, but it has never been recovered.
Barbeault seems to have started his criminal career after his mother passed away, having suffered breast cancer. Two weeks after her death, the attacks began to occur, and it is speculated that the death of his mother was the catalyst.