Escape is a person leaving official detention without authorization whether on his own or with the aid of others. Official detention includes: arrest, the period between arrest and being charged with a crime, detention before and during criminal proceedings, or during imprisonment. It also includes failing to return after a temporary leave granted for a specific purpose or period.
A 1993 report shows an average 16% escape rate from high security units in Dutch prisons. With a population of approximately 15 million, the Netherlands has nearly 8,000 cells in some 60 prisons of which fewer than 50 cells in each penitentiary are classified as high security units. In the first five months of 1991, there were 67 escapes from English and Welsh prisons, a rate of around 3 per week and nearly double the average rate for the previous three years.
In 1993, convicted Brazilian murderer Darly Alves da Silva and his son escaped from a lightly guarded "maximum security" prison that had no outside wall, no functioning guard towers and no searchlights. Da Silva was favoured with presents and privileges by police sympathetic to his killing of Francisco (Chico) Mendes Filho, a leader of a union of rubber tappers whose livelihood was threatened by deforestation carried out by ranchers, of whom the murderer was one.