DNA testing- how long does it take?
I want to keep all of my facts straight so is there anyone out here that has an idea of how long it takes to test a DNA sample? I mean, after investigators have bagged and tagged their evidence and the medical examinor lifts what ever pertinent materials from a body, how long does it take to test the evidence for DNA indentification: male or female, national origin, approximate age, etc.? In every book or journal I've read there hasn't been a single time frame given for me to go by. Can anyone help?
I use answers.com
It says 5 to 10 days.
I would imagine the workload would come into play as well.
Last edited by Branwyn; 03-10-2006 at 07:27 AM.
Five to ten days is about right, but it may be six weeks before anyone has time to test those particular samples. DNA labs can get horrendously backed up.
The Medical examiner should know from the cadaver the sex, race, and approximate age of the victim. To determine ethnicity or do even a partial genetic mapping would take much longer than 5-10 days.
It really depends on the particular DNA test, on the amount and quality of the DNA you have, and on what you're after. DNA tests can take a long time, but if you have quality DNA, and you do ordinary marker testing, the kind nearly always done, the process usually takes five to seven days from the moment the process starts.
Originally Posted by Anya Smith
The process can also be "pushed," if it's urgent enough, as it sometimes is in a serious criminal or medical case, and all the DNA results usually needed for forensic evidence or medical treatment can be obtained within seventy-two hours.
The lab our local police uses almost never takes longer than seven days to return results, though one case about a year back did take twice this long because the DNA wasn't of very high quality. I don't think a test has ever come back in three days, but I know results have been obtained in four days on several occasions.
Ethnicity can't actually be determined from DNA testing, no matter what tests you run. All that can be determined is probable ethnicity, which is why on such shows as CSI, the report always comes back with the word "probable." These probabilities are often remarkably accurate, and far too often, completely wrong.
Nor can age be determined through DNA testing.
Gender can nearly always be determined, but rare circumstances can even throw this off.
Assuming teh DNA sample has not degraded to a high extent, or has not been contaminated, everything a criminal investigation needs or can use will be returned with the five to seven day test, and pretty much everything a medical case can use will also be returned with a five to seven day test.
Thanks everyone. That helped a boat load!
As per an earlier quote, this was evidence pulled from a corpse pertaining to the killer; skin under the fingernails, hair fibers around the scene, etc. I didn't know that the examiners could "push" for quicker results. That's good to know.
They can push, but it's much more expensive, and is only done in a real emergency. When you can get results in five to seven days, there's seldom reason to demand them in three, though it does happen.
Originally Posted by Pike
New Fish; Learning About Thick Skin
Doesn't make scence
I understand that DNA labs can get backed up, but for how long? A friend of mine was murdered over a year ago and the suspect was indicted quickly. However, both the prosecution and the defense postponed the trial for DNA testing. It's been over a year! How long should I expect to wait???
I would suggest contacting a lawyer, in this case. It's beyond the scope of AW.
Originally Posted by maradaly
In some states, due to financial reasons, collected items with potential DNA evidence may never be processed--especially if there is other evidence which meets the legal threshold and/or is enough to convict on its own.
Now many states are too strapped to fund their own labs and the federal labs are severely overwhelmed. Arizona threw away thousands of samples from SexualAssaultExamination kits because they could not afford to store them let alone process them. The legal timeliness factor breaks many cases at the consideration point. (Is this worth the time & money to prosecute and will there be a positive result?)
Its not just the cost of equipment and security, its the time and expertise needed to train new people in processing. It is a human-and-machine collaboration involving very delicate samples which degenerate over time.
Even with everyone going full bore on a case, like Michael Jackson, there are some processes which cannot be rushed. I am sorry about your friend, maradaly, but it reads like the case is considered important enough to go forward. Pressuring the prosecution for results which are most likely out of their control would not help.
ETA: I don't know what state you are in, but in Iowa, the prosecution gets two delays and then the defense can have unlimited delays for cause. It took nearly two years for a recent major case to get to trial because everyone took every option. Justice has to have patience.
Last edited by Alphabeter; 07-31-2009 at 10:28 AM.
Writing is a lot like sex.
At first you do it because you like it.
Then you find yourself doing it for a few close friends and people you like.
But if you're any good at all...you end up doing it for money.
New Fish; Learning About Thick Skin
Paternity testing reports are typically a little of both at times. Back logs can cause major delays, the test itself takes 5 to 10 days to run the test itself, and the type also has something to do with it at times.
Now way in heck you'd get DNA results back in 5-10 days in Texas! For a murder case with good DNA you're looking at several weeks, with a push from the case detective/prosecution. Regular testing is taking up to six months, sometimes longer. Crazy, I know.
Here's an interesting note from a Federal Sex Crime Prosecutor:
There is a scandalous backlog of rape kits in the United States. After someone is sexually assaulted, the police will ask her to voluntarily undergo a Sexual Assault Nurse Examination (also called a SANE or a rape kit).
... Swabs are taken of the victim’s mouth, vagina, thighs and anus; clothing is collected; photos are taken; hairs are plucked from the head and pubic area. It is a long and unhappy process, but crucial to collect forensic evidence like semen, saliva, blood, and hairs which may contain DNA and other evidence.
In many cities, though, there’s a ridiculous backlog of rape kits sitting in warehouses, gathering dust. It’s estimated that 400,000 kits in America remain untested. Some cities are doing better than others – New York has no backlog, while Detroit has 16,000 untested rapes kits. DNA testing today is incredible, with the power to definitively solve crimes like never before. We have a national databank of DNA called CODIS, which holds the DNA profiles of eight million convicted criminals – but it’s only a useful tool if we actually compare these to evidence taken from unsolved rapes. The failure to process the backlog of sex kits – which could help solve countless brutal crimes – is a national tragedy.
I'm going to lock this up, as it's an old thread and really belongs in the Experts room. If anyone has more questions about DNA, please post there!