"Twice Ganimard has caught him.
Once he had him in prison, and actually brought him to trial.

Lupin became another man, and was let go from the very dock." "Really?
It sounds absolutely amazing," said the Duke.
"And then, in the affair of the Blue Diamond, Ganimard caught him again.

He has his weakness, Lupin--it's women.

It's a very common weakness in these masters of crime.

Ganimard and Holmlock Shears, in that affair, got the better of him by using his love for a woman--'the fair-haired lady,' she was called--to nab him." "A shabby trick," said the Duke.
"Shabby ?" said Guerchard in a tone of utter wonder.