The Daily Item, Sunbury, PA


April 17, 2013

Slate's Explainer: Explosions Often Leave Valuable Clues

Boston — In the aftermath of Monday's bombing at the Boston Marathon, investigators are working a 12-block crime scene to determine what kind of bomb was used and what kind of bomber — domestic or international — planned the attack. What sort of forensic evidence do explosions leave behind?

Bomb fragments, residue from the explosive, bits of electronics, and sometimes even the bombers' own fingerprints and DNA. One of the first things investigators do at a bombing site is determine what kind of explosive was used. There are a few ways to do this. For example, forensic scientists can use a handheld ion mobility spectrometer to sniff the air around the blast for traces of the explosives. (This is similar to what's used by the Transportation Security Administration if they ask you to step into a puffer machine.) Some of these devices can identify the specific type of explosive in the air, which is named in a digital readout. Other investigators may run color tests, in which bomb residues are applied with solutions containing reagents that change color in response to specific explosives. Both of these tests are considered presumptive and can be confirmed with procedures like chromatography and mass spectrometry back at the lab.

If the explosive is unusual, investigators may be able to determine where it was purchased. For example, some explosives are tagged with chemical markers, called taggants, that identify where they came from. If the explosive, on the other hand, is TNT, you know it was probably stolen, and you can look over the mandatory theft reports filed to the Bureau of Alcohol, Tobacco, Firearms and Explosives, which requires photo ID for all purchases. (These thefts are reported many times a year, but investigators may be able to incorporate evidence connected with the thefts into the bombing investigation.) Unfortunately, if the explosive is homemade from common ingredients, such as fertilizer or gun powder, then the chemicals are difficult to trace.

Text Only
  • Prize claim cost man $1,829

    WINFIELD — Western Union is doing what it can to educate people about the risks in wiring money. An entire section on its website ( is devoted to providing information that might reduce the risk of people falling victim to fraud schemes.

    April 19, 2014

  • Reel good time enjoyed by 200 young anglers

    TREVORTON — It only took about three minutes for J.C. Wallish to reel in his first fish at the Little Shamokin Creek Watershed Association’s annual Youth Trout Derby on Saturday.

    April 19, 2014

  • Elytte Barbour's 'bad trip' put him on the road to prison, friend says

    SUNBURY — A former roommate of slaying suspect Elytte Barbour drove 450 miles from North Carolina to spend 45 minutes in the Northumberland County Prison with his best friend last week, and was not surprised when he heard Barbour say: “I am afraid to spend the rest of my life in jail.”

    April 19, 2014

  • bonehunt20a.jpg 60 dogs battle for biscuits at annual bone hunt

    It was a scene similar to ones playing out all over the nation this weekend: nervous parents holding baskets and bags, watching their little ones search for goodies in the grass.

    April 19, 2014 1 Photo

  • Arizona tribe set to prosecute first non-Indian under a new law

    PASCUA YAQUI INDIAN RESERVATION, Ariz. — Tribal police chief Michael Valenzuela drove through darkened desert streets, turned into a Circle K convenience store and pointed to the spot beyond the reservation line where his officers used to take the non-Indian men who battered Indian women.

    April 19, 2014

  • Danville parents hope strike ends quickly

    DANVILLE ““ First-grader Madison Wild was sad she missed school Thursday.

    April 19, 2014

  • Schools ask state to waive 180-day rule

    Three area school districts have asked the Pennsylvania Department of Education to add up their hours instead of their days in order to reach the required amount of instruction time in the school year.

    April 19, 2014

  • Former Bucknell star in NBA playoffs

    ATLANTA — It really hit Mike Muscala a few days ago when he was listening to the Nets’ starting lineup at the Barclays Center in Brooklyn.

    April 19, 2014

  • State: Discard raw milk from Greenfield Dairy

    MIDDLEBURG — Consumers should discard raw milk purchased recently from the Greenfield Dairy of Middleburg, which also has temporarily suspended production after Listeria monocytogenes was discovered in the product following routine testing, the state Department of Agriculture announced today.

    April 18, 2014

  • Penn State police: Three posed nude at Nittany shrine

    STATE COLLEGE — Penn State police say three male students who reportedly posed nude for a photo at the university’s Nittany Lion Shrine face school discipline.

    April 18, 2014

The Daily Marquee

How do you eat your chocolate Easter bunny?

Feet first
Tail first
Ears first
     View Results
Photo Galleries
The Valley


Click HERE to read all your Parade favorites including Hollywood Wire, Celebrity interviews and photo galleries, Food recipes and cooking tips, Games and lots more.