PDA

View Full Version : DNA helps solve crimes



IceTea
31-10-02, 02:55 PM
Monday, May 13, 2002

DNA helps solve crimes
By Elizabeth Lynch
Poughkeepsie Journal
==============================================
More than 102,000 samples have been taken for the statewide DNA database and the governor's office would like to see that number grow even larger by expanding who is required to submit samples.
DNA, deoxyribonucleic acid, is the molecular basis of heredity in many organisms. Each human being's DNA is unique, which makes it a useful tool in police investigations. DNA can be extracted from everything from blood, to hair and skin samples.

The samples are used not only to help convict people, but also to clear the innocent. Since 1999, DNA samples yielded suspects in 308 open cases statewide.

''It truly is a double-edged sword,'' said Ulster County Public Defender Paul Gruner. ''It can be used to clear people wrongfully convicted.''

Just last week, DNA was used to clear a Tennessee man who had served 22 years in jail for a rape he didn't commit.

Eye witness identifications are not always accurate, said Gruner, and DNA can be invaluable in proving someone's innocence, even years after they have been convicted.

''It can it be used as a tool for law enforcement certainly, but once again, if the DNA is there, it's there. If it's not, they don't have a case,'' Gruner said.

108 cleared of crime

The Innocence Project, a nonprofit legal clinic based at the Benjamin N. Cardoza School of Law at Yeshiva University, has used DNA evidence to clear 108 people who had been wrongly convicted of crimes.

DNA ''provides certainty for victims as well as the wrongly convicted,'' said Nina Morrison, executive director.

The Innocence Project is working to ensure that existing databases are properly funded and to include crime scene evidence in those databases. There also are privacy issues that must be addressed, Morrison said.

Suspects often voluntarily give DNA samples to exclude themselves. Those samples should be destroyed, Morrison said.

''There is no right for the authorities to keep them and put them into a database,'' she said.

There is also a danger that the database can be used to profile -- to use genetic analysis to determine if an individual has a propensity toward crime.

''The American public has to know that it's being used for the purpose it was authorized for,'' Morrison said.

New York State created its DNA database in 1994. At the time, the law only required those convicted of 21 specific violent and sexual offenses to submit samples. In 1999, the law was expanded to include arson, kidnapping and some nonviolent offenses, such as drug crimes. The expanded law also required those on parole or probation to submit samples.

Gov. George Pataki has proposed expanding the list of crimes to include misdemeanors.

''The governor wants to expand it to include all convicted criminals regardless of the crime,'' said Caroline Quartararo, a spokeswoman for Pataki.

Felon DNA added to database

Of the more than 102,000 samples taken, about 87,000 have been analyzed. Samples from about 65 percent of the prisoners convicted of a felony are added to the database annually. That's about 30,000 samples a year, Quartararo said. The database also includes about 4,350 samples from crime scenes.

The goal is to ''include (the DNA) all convicted criminals, just like fingerprints,'' Quartararo said.

There have been efforts by prisoners to refuse to submit samples, most recently in California, but the laws have held up to constitution challenges.

''The state has been enforcing that law,'' said Al O'Connor, an attorney with the state Defenders Association.

''My concern as a pastor or prison minister is the whole issue of justice,'' said Rev. Alfred Twyman, a prison minister, who said he hears very little debate or discussion about the database.

Last October, DNA helped City of Poughkeepsie police obtain a confession in a stabbing case. The suspect maintained her innocence until she was confronted with the DNA evidence, said Edward McLoughlin, a senior assistant district attorney for Dutchess County.

''It is as much of a sword as it is a shield,'' McLoughlin said.

In New York, the state will pay to have a DNA test conducted for prisoners who claim they are innocent, but can't afford to pay for the test, Quartararo said.

The decision is designed to make the criminal justice system as ''fair has humanly possible,'' Quartararo said. ''There's nothing positive to the state to have the wrong people in prison.''

==============================================

Any idea if this method used in Oman or any other countries ? and how effective is it ?

Wanderer
31-10-02, 07:44 PM
It's less effective when all of the population is extremely closely related due to inbreeding.

Neena
31-10-02, 07:44 PM
God has given every human being a different DNA to everyone. Even the identicle twins would have different DNS's. And thats one of the powerful method for sure is used in this world to identify a crime and many other issues as well.

Wanderer
31-10-02, 08:26 PM
I believe identical twins have the same DNA.

Leading them to be .... identical.

FaHaD
31-10-02, 11:12 PM
well DNA finger printing.. is a new technology which is used to differntiate one person form another even by a drop of blood or small part of hair or even saliva...
DNA is basicly made of 4 bases which are joined together making diffent sequences . e.g AGTCATCGGGCCT..ETC
some of these sequences get repeated throughout th genome and they are called tandem repeat and one kind of these tandem repeat is called Variable Number Tandem Repeat (VnTR), which is used for finger printing...

indentical twins ( monozygotic) got simmilar DNA sequences but with a very very very very small diffenet , i can't remeber the percentage of difefrnce .. and i am not sure wether this difefrnce can be detected by VnTR identification

Wanderer
01-11-02, 02:05 AM
Originally posted by FaHaD
...indentical twins ( monozygotic) got simmilar DNA sequences but with a very very very very small diffenet , i can't remeber the percentage of difefrnce .. and i am not sure wether this difefrnce can be detected by VnTR identification

Actually, this is very interesting stuff.

What I found is that identical twins start with the same DNA "fingerprint", but that small changes begin once either of the twins gets exposed to viral infections - the virus will insert some of it's DNA into the host's DNA or trigger DNA changes due to immune system responses - thus creating differences.

However, current criminal forensic DNA analysis focuses only on 13 loci and would miss small viral changes completely - thus identical twins could not currently be distinguished.

An interesting article:

http://www.ojp.usdoj.gov/nij/dnamtgtrans9/trans-f.html

FaHaD
02-11-02, 01:56 PM
indeed an intretsing information.. but i wonder about that article is it just a deductice theory i mena not biuld on data..

genes canbe modified by some ways. due to enviromental factor and some errors in DNA repair mechanisms.. and i don't know may be these can conribute to teh minor gene difference between monozygotic twins..

kuwait has started investigation by using DNA finger printing.. and i don't know wether omani police will use such a method or not.. it is a reliable method for investigation of a crime.. but i don't have an idea about cost effectiveness of such a method if compared with teh current methods of investigation..