"Drug gangs take advantage of them by offering them large payments. They also think they are less likely to be searched."
Earlier this year, British pensioners Roger and Sue Clarke were convicted of smuggling £1 million pounds of cocaine on a luxury Caribbean cruise.
A judge in Lisbon, Portugal, sentenced them to eight years in prison.
But in Colombia, one of the reasons gangs use senior citizens to move their drugs is that they often get away with non-custodial sentences, according to the police. Pensioners convicted of crime are usually placed under house arrest or a temporary curfew.
"The risk for them is therefore considered to be less so it's easier to persuade them to try," said colonel Siza.
Very few drugs mules are repeat offenders, according to the Colombian authorities, but Mr Ruocco, who is currently in custody awaiting trial in Bogotá, had previously been detained at Heathrow airport after arriving on a flight from Togo with 2.5kg of cocaine in his luggage in 2014.
He was found not guilty of the offence in April 2015.
Approximately 70 per cent of the cocaine consumed globally comes from Colombia.
The country also seizes more cocaine than any other in the world, although the total amount of seizures dropped by 4.7 per cent, from 434.7 tons in 2017 to 414.5 tons in 2018.