"If you want proof that he's alive, we'll send you three of his fingers."
These chilling words were among the last Juan Carlos Blumberg would hear from the kidnappers of his 23-year-old son, Axel.
Days later, the blue-eyed university student was dead, brutally beaten and murdered as he tried to escape his captors.
Axel Blumberg is just one of about 200 people kidnapped in Argentina so far this year - though experts believe many abductions go unreported.
Over the past two years, the number of kidnappings in the country - long regarded as one of the safest in Latin America - has increased more than fivefold.
In the same period, victims have handed over up to three billion pesos ($1bn) in ransoms, according to Alex Zunca, a security adviser to the province of Buenos Aires and a sometime bodyguard to the likes of Madonna and David Copperfield.
The latest Citizen Security Monitor survey, carried out by Argentina's Ministry of Justice, suggests that one in every 10 residents in Buenos Aires now fears being kidnapped - that's 300,000 people.
Many of these were doubtless among the 200,000 demonstrators who heeded Juan Carlos Blumberg's call to gather peacefully in the centre of Buenos Aires earlier this year, for two rallies demanding greater security and stiffer penalties for criminals.
Not since Argentina's economic meltdown a little over two years earlier had this many people taken to the streets, and all because Mr Blumberg's tragic loss touched a chord in a society too often disinterested in issues which have no direct effect on their lives.
Sitting in the cluttered living room of his home in the middle-class commuter town of Martinez, Mr Blumberg said it was seeing his only child's lifeless body in the local morgue which propelled him into action.
"He was covered in bruises, he had no nails; the boy was massacred," he said, as he broke down in tears.
Blumberg's campaign has struck a chord with many Argentines
"It was terrible. For me, that was when I swore that I was going to find the people responsible. I swore I would fight to make sure this doesn't happen to other youngsters and that's what I am doing."
Mr Blumberg's one-man "Crusade for Axel" has already had results by forcing the Argentine government to hastily cobble together a national security plan - which includes the creation of an FBI-style agency - and possibly lowering the age of criminal responsibility to 14.
But Argentine governments have a history of making promises they cannot keep.
So will this battery of new security measures ultimately have any effect?
"I think so," Mr Blumberg said, "because there are people taking part in these demonstrations from all over the country and we have five million signatures [for his petition demanding greater security].
"So the politicians will be obliged to make these changes because the people will demand it. And if they don't, in the next election, these people will be out of a job."
One of the politicians under more pressure than most is the new security minister for Buenos Aires province, Leon Arslanian.
His biggest challenge will be to reform the notoriously corrupt Buenos Aires provincial police force, which has been shown to be involved in several kidnappings - though in the Blumberg case it is just accused of bungling.
Arslanian is recruiting more officers and purging the ranks
Mr Arslanian has already begun recruiting up to 2,000 new officers.
And he has sacked scores of policemen accused or convicted of crimes.
But he can do little to tackle the root causes of crime, such as poverty, unemployment and an abysmal education system.
He told the BBC: "My expectation is to carry forward a process of change and transformation which allows the police to be trusted by the country, by its community, to be able to prevent and solve crimes, and to carry out successful investigations.
"The community wants there to be no more crimes, it wants to live in peace."
So far, there is little sign that either of these is happening.
According to Argentine media reports, Buenos Aires now has one reported kidnapping every 48 hours.
And so long as the situation fails to appreciably improve, Mr Blumberg has vowed to continue fighting his crusade.
"When we get them to pass the laws, when all those murderers are in prison, and when the people can live in peace - so the criminals are not the ones who are in the street, and we, the decent people, have to hole ourselves up in our homes behind bars - that's when my job will be done."