said, 'What a shame that I let you escape,' And then he made a gesture like he was slitting someone's throat. I left everything dumped there, and fled with the clothes I was wearing. They didn't give me time to get anything else."

She now lives in Bogota, supported by friends. "What else am I going to do? I'll keep on fighting," she says.

Jailler's death came in a wave of executions carried out with almost complete impunity by the Colombian army, according to Ramiro Orjuela, a Bogota-based lawyer working for victims of state violence. In the Meta province alone - a cattle-ranching region south-east of the capital - 300 people have been killed since 2006. The army's 12th Mobile Brigade operates there, and is believed to be responsible for most of the killings.

I met Mariel Munoz just as the news was emerging of the capture of FARC leader Nelly Avila Moreno (right), known as Karina, wanted for a string of murders, abductions and extortion. Karina - women make up more than a third of the ranks of FARC - was reported

to be "nearly dying of hunger" when she handed herself in after President Uribe guaranteed her safety if she surrendered.

However, behind the government celebrations of Karina's capture, and of the recent high-profile raid into neighbouring Ecuador to execute FARC's number two, Raul Reyes, the army's casual slaughter of innocent people continues.

As John Lindsay-Poland, of New York's Fellowship for Reconciliation, puts it, the killings are easy: the army are rarely if ever prosecuted for killing civilians, and they measure success by body count. "The predominant proclamation of success is how many guerrillas were killed in combat. There is seldom any punishment for killing a civilian." Out of 955 reported cases of military killings of civilians over five years - including 'false positives' - only two have resulted in convictions.

Mariel Munoz recalls the moment she confronted the officers who confirmed they had killed her son. "They laughed, right there and then."