In Polygraph by Robert Lepage and Marie Brassard, the lectures on criminal science and political science may literally overlap in that the authors are drawing a comparison between criminal activity that takes place within society and also in politics.
The political aspect of this scene centers on the Berlin Wall; the criminal aspect deals with a cold case—the report of an inquest regarding a murder victim six years prior.
However, there are many questions left unanswered in the play.
Francois enters, like a predator...
The audience does not know if Francois is capable of murder. "Predator" offers a striking description that colors the way the audience reacts to him, especially in light of his masochistic tendencies. Francois was also a friend of the murder victim, and a suspect. Francois is heard making "violent and lamenting cries" through the wall that separates his apartment from Lucie's. When Lucie asks Francois at one point if he killed the dead girl, he says that he doesn't know anymore. Is this a tortured soul responding out of guilt, or because he has been a suspect for six years and he starts to mentally fall apart?
A great deal of the political science lecture mirrors the movements of the murderer, shared in the forensic report:
...by the slicing action of the knife...
This refers to how the city was "sliced" in two by the Allies, and how the victim was hurt while trying to defend herself. The separation of the city is compared to the cut that killed the young woman's life:
Right through the heart...
This metaphor extends its way through both lectures. And while it may speak to the devastation of politics and its similarity (in this case) to murder, it also raises questions about Francois' possible involvement in this unsolved murder—questions that are never answered.