Eventually to South America.
Before leaving, there is a medical requirement.
A vaccination.
Perhaps you hesitate.
But you have already committed.
Your money is packed.
Your family believes you are escaping.
If you vanish that night, they may spend weeks believing you succeeded.
That psychological mechanism is what separates Petiot's crimes from a random series of murders.
The trap began before the victim arrived at 21 rue Le Sueur.
It began when Petiot made disappearance itself desirable.
The House as Evidence
During the fifth hearing of the trial, judges and jurors visited the property.
That visit mattered because diagrams cannot communicate everything.
A courtroom can turn a crime scene into abstract language.
Door.
Room.
Cellar.
Pit.
Boiler.
Observation hole.
Standing inside the actual building changed the scale.
The Ministry of Justice later wrote that the site included double doors, a gas chamber fitted with a peephole, and a quicklime-filled well.
A juror could see the distance between rooms.
Stand where a victim might have stood.
Look at how a door closed.
See the restricted exits.
Understand why these features were difficult to explain as normal parts of a physician's house.
The property silently contradicted Petiot's claim that this was simply an improvised wartime execution site.
It looked organized.
Repeated.
Prepared.
How Did He Kill Them?
This is where careful storytelling matters.
Popular accounts often present one simple method as though every death were documented minute by minute.
The actual case is less neat.
Some evidence and later accounts indicate injections were part of the method, with Petiot allegedly presenting them as vaccinations needed before travel.
The official Ministry of Justice also describes a gas chamber-like room with an observation peephole.
Remains were burned or treated with quicklime.
But not every individual's precise cause and sequence of death can be reconstructed with certainty from the surviving record.
That uncertainty is part of the case.
Petiot destroyed the bodies partly to destroy the answers.
Investigators could often identify the system more confidently than the final mechanism used on each person.
So the strongest fact is not:
He killed every victim in exactly the same way.
It is:
He built an environment in which vulnerable people entered expecting escape, were separated from the outside world, died, and had their remains systematically concealed or destroyed.
That is more disturbing than any single method.
Why the Victims Did Not Run
One of the most common questions asked about deception-based serial killers is why victims trusted them.
The question usually begins from knowledge the victim did not possess.
We know Petiot was dangerous.
They met a doctor.
We know the escape network was fraudulent.
They lived in a world full of real clandestine networks.
We know a supposed vaccine could be part of the trap.
They were preparing to cross international borders during wartime.
We know bringing valuables concentrated their wealth for theft.
They knew they might need money wherever they arrived.
The victim's behavior was rational within the false world Petiot created.
That is what effective predators do.
They do not always convince people to do irrational things.
They provide false information that makes rational choices lead toward danger.
The Suitcases
The suitcases recovered in the case became some of the most haunting physical objects associated with the prosecution.
They were not random luggage.
They represented belief.
Every suitcase meant someone expected a journey.
Someone packed.
Someone selected what to leave behind.
Someone decided what could fit.
Maybe photographs.
A coat.
A shirt.
Cash.
Jewelry.
Documents.
Then that person disappeared.
The luggage remained.
At the trial, the objects created a physical counterargument to Petiot's heroic persona.
A Resistance executioner might claim he killed enemies.
Why then were there suitcases belonging to people who thought they were fleeing?
Why were personal valuables retained?
Why were traces of identification altered or removed?
Why did families receive misleading information after disappearances?
The material evidence told a robbery story.
Money
The prosecution argued that profit sat at the center of the killings.
The Ministry of Justice says Petiot seized victims' belongings before killing them, and the ultimate location of much of the loot was never determined.
That unresolved money matters.
A patriotic execution story becomes less convincing when the accused repeatedly benefits from the victims' disappearance.
This does not mean every action can be reduced to one simple motive.
Serial offenders can have overlapping motives.
Control.
Theater.
Greed.
Violence.
Power.
But material gain was not incidental.
His system specifically encouraged victims to bring portable wealth.
That was built into the process.
If robbery were irrelevant, the travel instructions make much less sense.
The War Ends, the Story Changes
When Petiot disappeared in March 1944, France was still occupied.
When he was captured in October, Paris was free.
The change transformed what defenses were available.
During occupation, openly claiming Resistance membership was dangerous.
After liberation, it could become a shield.
People scrambled to establish wartime credentials.
Some genuine Resistance members emerged as heroes.
Others exaggerated minor roles.
Some collaborators attempted to reinvent themselves.
Petiot stepped directly into that confusion.
Captain Valรฉry.
Military security.
Patriotic documents.
Resistance language.
He was not simply hiding physically.
He was trying to hide historically.
If he could become a Resistance figure before authorities found him, perhaps the discoveries at rue Le Sueur could be reclassified in the public imagination.
Not murder.
War.
Not victims.
Enemies.
Not theft.
Confiscation.
Not a false network.
Secret operations.
That was the final great deception of Marcel Petiot.
He tried to make the historical context that had hidden his crimes also excuse them.
"I Killed Enemies of France"
At trial, Petiot's stance became increasingly bold.
According to official and contemporary accounts, he claimed dozens of killings, far more than prosecutors had charged, while insisting the dead were enemy agents or collaborators.
Strategically, this was clever.
A complete denial would have forced him to explain the house.
Human remains.
Victims' property.
Witnesses.
The escape network.
His flight.
The architecture.
The luggage.
Too much.
So he conceded the irreversible parts.
Yes, people died.
Then changed the meaning.