Yet Another GPS Tagging Trial
Why does this this article in The Times about Yet Another GPS Electronic Tagging Trial in the UK, manage to get even the basic facts about how the technology works completely wrong ?
"'Spy in the sky' systems to track sex offenders
By Richard Ford, Home Correspondent
SEX offenders and wife beaters will be tracked by spy in the sky satellites in test schemes to be launched by the Home Office in September "
The illustration to the article provides a better idea of how the Pro Tech technology works. It is utter nonsense to claim that:
"The satellite can tell where a person has been in a given period of time, when a person is approaching an area from where he is banned and even every move a person makes. The system works by placing an ankle bracelet on the offender which is then linked electronically to a mobile tracking device clipped to his belt. The device sends signals to the satellite allowing the offender?s movement to be monitored. "
No! The GPS satellites have no knowledge at all of the position of the tracking unit - they only transmit their synchronised time/position signals down to Earth not the other way around.
We are completely sceptical about whether this technology should ever be used to monitor dangerous criminals or those sex offenders who are highly motivated to re-offend. It has potential uses for those petty offenders on bail or parole who would not have been a risk to society in any case, with or without an electronic tag. To attempt to extend the acceptable categories to more dangerous prisoners, on the grounds of "cost savings" is complete folly.
What works in the wide open desert spaces of the southern USA, simply does not work in the crowded urban areas of the UK where either trees or buildings often obscure the direct line of sight needed to at least 4 GPS satellites in equatorial geostationary orbit, low down in our northern latitude skies.
GPS cannot be used to enforce "no go zones" indoors or inside of closed sided vehicles like vans, which have been the favourite tools of many predatory child molesters and rapists.
There are several ways in which the technology can be spoofed to provide these highly motivated people with an alibi, once it becomes more than a novelty. The reliance on mobile phone technology rather than on more traditional fixed telephone lines for the base unit to communicate with the central control system is another area of weakness which will be exploited.
Even if the technology works, there is no guarantee that the system to enforce it does.
The case of Lawrence Napper a convicted rapist, in Texas, who, despite still wearing the Pro Tech tracking technology, managed to rack up 440 "parole violations" and thrteen arrest warrants in 9 months, including returning to the supposed "no go zone" campus where he had committed the rape, and eventually was arrested for allegedly molesting a 6 year old boy.
He was not re-arrested and sent back to prison, because officials were trying to justify the "cost savings" of the tagging project, and sending too many people back to prison would have cast doubts on the cost effectiveness of the scheme, and presumably on their careers.
This sort of bureaucratic nonsense, leading to tragic consequences, is all too likely to happen in the UK as well, once the novelty and high intensity scrutiny of the pilot project has worn off.
Just to show how modern police forensic technology is not infallible like it seems to be on the popular TV series "CSI: Las Vegas" or "CSI: Miami", the Houston Police Department's DNA testing lab which processed the samples in the Lawrence Napper case has been shut down for incompetence
"The HPD's DNA lab was shut down in December 2002 after an independent audit revealed poor scientific methods and substandard working conditions at the facility"
"The district attorney's office is reviewing evidence processed by HPD's DNA lab in almost 400 cases. To date, 293 cases have been retested. Of those, 61, or about 20 percent, have shown problems or the need for additional testing and review."
"Most of the problems identified so far have been the result of a lack of evidence to retest rather than definitive proof that evidence was mishandled by the HPD lab. However, critics of the review process have complained that many of the retests have been conducted on evidence extracted from the original source -- evidence that they contend is suspect since the extractions were performed by the HPD lab."
" In 2001, Lawrence James Napper was convicted and sentenced to life in prison in the kidnapping and sexual assault of a 6-year-old boy.
However, according to Munier, retests produced a DNA profile that belonged to neither the victim nor Napper.
Weaker DNA markers tend to point toward Napper, but the final results were inconclusive, Munier said."
CORRECTION: thanks to those people who have reminded us that GPS satellites are mostly not geostationary about the equator.
"GPS has poorer coverage the further you go from the equator, but the GPS satellites are NOT geostationary, they are in a 55 degree inclined orbit, which gives poorer coverage away from the equator.
There are 4 augmentation satellites (WAAS and EGNOS systems) that ARE
geostationary that can also be used for navigation, but the 24 GPS
satellites are NOT geostationary."