How reliable are gunpowder residue tests in homicide investigations?
613756
pretty damn reliable....
600923
First of all - it won't fit in our weapons. \n\nNext is the fact that their ammunition does not meet our safety standards.\n\nNor does their ammunition meet our reliability standards.\n\nAnd we do not know if that ammunition has been properly maintained or stored.
678542
A bullet can not really be "traced" to a particular gun but it can be matched with other bullets fired from the same weapon. Most ballistic experts will be able to ascertain the type of gun a bullet was fired from by the bullet type and other characteristics. They can't match a bullet to a gun however until they have the gun in their own hands. \nAt which time they test fire the gun into water or gel and then recover the bullets. It is at this time, that under a microscope they can match the markings on the two bullets. These come from the inside of the gun barrel which is not microscopically smooth.
534422
No possible way of knowing that since nobody (I am quite sure) has gone back and tried to determine whether the particular DNA evidence used in all those cases was "accurate" or "inaccurate."  In general, however, it is my belief that when performed properly and correctly used, DNA evidence is virtually infallible.
415828
Hope this is it.\n\nhttp://www.manhunt.com/reviews/html/702.html
673014
Sadly, nothing appears to be wrong.\nAs of 12:34 EST\n""Senate Sergeant at Arms Bill Pickle told Reuters there were no reports of any arrests or injuries though several ambulances were brought to the scene.\n\n"We have been told by staff of shots fired and the smell of smoke," Pickle said. He later raised the possibility that a firecracker might have been the cause.""\nThey are still under lockdown, but searches have turned up nothing.
1142154
hi pinku. its the science which deals with guns and bullets. when ever a bullet is fired, it gets scratched by the barrel of the gun in a particular way. it is totaly unique. no other gun can creat the same type of scratches on the bullet. its like the finger print of humans. when ever a crime takes place, it can be found out from a group of guns that from which gun was the bullet fired. and from that gun's licence number, person can be identified. thus, forensic experts use this technique to catch the culprit. \nto do this, a bullet is fired from the gun in the laboratory. it is fired at a certain angle in water tank that prevents it from getting scratched from any other outer obstacle. then the bullet is put under microscope and its photograph is taken. same is done with the bullet which is found on the crime scene. then both the photographs are matched.\nalso, it can tell the distance from which the bullet was fired. when ever a bullet is fired, it gets heated up due to gunpowder burning. this results in burning of human skin when it enters it. so, the greater the distance, less is the burn.\nit can also tell that which gun was used.\n\nhope that i was able to answer your question.\nNOTE:- bhai, kisi ko thok mat dena! hahaha......\n\ngood luck!
806999
The police and district attorney, anywhere, don't like to admit they made a mistake.  My guess is you will get no cooperation unless you can come up with some concrete evidence, to use, to get their attention.\nIf you have the finances, consider hiring a private investigator who has experience in investigating murder cases.\nLack of finger prints does not mean anything by itself.  Gun shot residue is always present on a shooter's hand, and you would have to see the investigation files to determine if residue was checked for and found, on the victim or anyone else at the scene.
190988
It has been done before so don't go trying to burn anything you wouldn't want to get caught doing.LOL JK But yes it is possible to detect charred remains no matter what is used to fuel the fire.
909645
Yes, it will. If it is a modern firearm that uses a cartridge.\n\nThe reason it will is that the black powder used in older firearms is composed of carbon (from charcoal), sulfer, and potassium nitrate (KNO3). The explosion of black powder is a chemical reaction that does not require atmospheric oxygen to procede. Potassium nitrate is the oxidizer in this reaction and can therefore take place in the vacuum of space.  Though I'm not certain about the chemical equation, I'm sure modern smokeless powders would be self oxidizers as well.\n\nEven the primers for the cartridges are made from a chemical that is sensitive to shock such as potassium perchlorate and does not require the input of oxygen to detonate. \n\nAs for the bullets flight. It does not require air to fly. In fact without air resistance, it will have better bullistic perfomance than on earth. It will maintain its muzzel velocity until something stops it. Such as an atmosphere, an asteroid, or an interstellar terrorist :>) . It would however still be affected by whatever gravitational field you happen to be in and would have a curved flight path though not the same as here on earth.
833296
They won't even go to trial!  The local DA will review the case after the department or State Police conducts an investigation.  Everything I have read shows that SHE shot first.  Whether she was 92 or 18, she shot first and the police responded with the same level of force.  Justified shoot with no legal recourse.  Local DA will go with whatever decision the investigating PD recommends.  Lesson learned for Grandma.....Don't bring a rusty wheel gun to a semi-automatic weapon firefight.
57815
BE VERY CAREFUL, then you can follow the instructions on the website: http://chemistry.about.com/cs/howtos/ht/gunpowder.htm\n\nDon't get into any trouble!
875436
Depends on the burning rate of the powder on how much propellant is in the case. If your that curious get a bullet puller, and weigh the ammo. If you are planning to handload DONT go buy the weight of the powder in a factory case. Burning rates are different from MANY different types of powders.
257041
No they shouldn't be. They are definitely a good investigative tool for law enforcement, but the results aren't totally reliable.
1166951
Crime Scene Investigations (Forensics)
967708
ballistics, forensic anthropology, pathology, entomology,\n\nwhere ever you find one form of forensic science you will find dozens more because no single science can solve the crime accurately
603636
Luminol.\n\nLuminol is a chemical that glows greenish-blue when it comes into contact with blood — even traces that are years old. To be exact, it reacts to hemoglobin, an oxygen-carrying protein in red-blood cells. Luminol is so sensitive, it can detect blood at 1 part per million. In other words, if there is one drop of blood within a container of 999,999 drops of water, luminol will glow.\n\n\nInvestigators typically use luminol at crime scenes where no blood is visible. They spray the chemical over a wide area in near-total darkness, so any reaction is obvious. Officers then photograph or videotape the result, using a flash technique that picks up the glow while making the area around it visible and identifiable on film, so the context of the crime scene isn't lost.\n\n\nBut does a glow mean there's blood present? Not necessarily. Luminol reacts to some metals, paints, cleaning products and plant matter. However, the chemical's reaction to each differs in intensity; metals, for example, cause an immediate glow that quickly fades, while blood glows longer. A specialist can tell the difference, and then perform more conclusive tests to determine whether the blood is human.\n\n\nLuminol also can point the way to further evidence or even to how events might have unfolded. For example, if luminol sprayed on a carpet produces a glow, officers might peel back the rug to reveal a floorboard soaked with blood. Or perhaps the glow discloses the direction in which a criminal walked or dragged a body, or whether the victim was shot from behind or above.\n\n\nSo, to anyone thinking that a carpet cleaner or a sponge and soap will erase evidence of their crime, take note. This is one stain that cannot be "shouted out."