The Villain in my story kidnaps people and transfers their souls into robot bodies, wiping their memories in the process.
This process has been going for a while, around thirty years. The current number of converted souls sits around 150 000. This means that every day, the Villain has to kidnap around twelve to fifteen people.
He has a victorian-age steampunk nation roughly the size of Greece at his disposal in terms of population. I haven't calculated the exact number, but the capital sits at around 3 million people.
My question is, how would the Villain (who does not control the government) manage to keep the daily disappearance of 15 people a secret, or otherwise discouraged the government / the police from investigating them?
We can assume most of these kidnappings would be from social groups with either high fatality rate (factory workers, coal miners,...) or those that don't concern the government as much (street thugs and the homeless, orphans on the street)
What is an effective way to keep such a large-scale operation undercover and sustainable?
At which point will it become unsustainable and the truth will come out?