Much of crime scene investigation, also called criminalistics, is based on the notion that nothing vanishes without a trace. This is particularly true of violent crime victims. A murderer can dispose of the victim's body and mop up the pools of blood, but without some heavy-duty cleaning chemicals, some evidence will remain. Tiny particles of blood will cling to most surfaces for years and years, without anyone ever knowing they're there.
The basic idea of luminol is to reveal these traces with a light-producing chemical reaction between several chemicals and hemoglobin, an oxygen-carrying protein in the blood. The molecules break down and the atoms rearrange to form different molecules (see Microsoft Encarta: Chemical Reaction for more information on chemical reactions). In this particular reaction, the reactants (the original molecules) have more energy than the products (the resulting molecules). The molecules get rid of the extra energy in the form of visible light photons. This process, generally known as chemiluminescence, is the same phenomenon that makes fireflies and light sticks glow.

What Does Luminol Do?

A simulation of luminol at work: Before spraying luminol, there's no sign of blood. After spraying luminol, the latent blood traces emit a blue glow.

Investigators will spray a suspicious area, turn out all the lights and block the windows, and look for a bluish-green light. If there are any blood traces in the area, they will glow.

Chemical Reaction
The "central" chemical in this reaction is luminol (C8H7O3N3), a powdery compound made up of nitrogen, hydrogen, oxygen and carbon. Criminalists mix the luminol powder with a liquid containing hydrogen peroxide (H2O2), a hydroxide (OH-) and other chemicals, and pour the liquid into a spray bottle. The hydrogen peroxide and the luminol are actually the principal players in the chemical reaction, but in order to produce a strong glow, they need a catalyst to accelerate the process. The mixture is actually detecting the presence of such a catalyst, in this case the iron in hemoglobin (see Microsoft Encarta: Catalysis for more information on catalysts).
To perform a luminol test, the criminalists simply spray the mixture wherever they think blood might be. If hemoglobin and the luminol mixture come in contact, the iron in the hemoglobin accelerates a reaction between the hydrogen peroxide and the luminol. In this oxidation reaction, the luminol loses nitrogen and hydrogen atoms and gains oxygen atoms, resulting in a compound called 3-aminophthalate. The reaction leaves the 3-aminophthalate in an energized state -- the electrons in the oxygen atoms are boosted to higher orbitals. The electrons quickly fall back to a lower energy level, emitting the extra energy as a light photon (see How Fluorescent Lamps Work for more information on light production). With iron accelerating the process, the light is bright enough to see in a dark room.
Investigators may use other chemiluminescent chemicals, such as fluorescein, instead of luminol. These chemicals work the same basic way, but the procedure is a little bit different.


Investigators Use Luminol
If luminol reveals apparent blood traces, investigators will photograph or videotape the crime scene to record the pattern. Typically, luminol only shows investigators that there might be blood in an area, since other substances, including household bleach, can also cause the luminol to glow. Experienced investigators can make a reliable identification based on how quickly the reaction occurs, but they still need to run other tests to verify that it is really human blood.
Luminol in itself won't usually solve a murder case. It's only one step in the investigative process. But it can reveal essential information that gets a stalled investigation going again. For example, hidden blood spatter patterns can help investigators locate the point of attack and even what sort of weapon was used (a bullet makes blood splatter very differently than a knife does). Luminol may also reveal faint bloody shoe prints, which gives investigators valuable information about the assailant and what he or she did after the attack.
In some cases, luminol leads investigators to more evidence. For example, if luminol detects trace amounts of blood on a carpet, investigators may pull up the carpet and discover a lot of visible blood on the floorboards below.
One problem with luminol is that the chemical reaction can destroy other evidence in the crime scene. For this reason, investigators only use luminol after exploring a lot of other options. It is definitely a valuable tool for police work, but it's not quite as prevalent in crime investigation as presented on some TV shows. The police don't walk into a crime scene and start spraying luminol on every visible surface.
For more information on luminol and other forensic investigation tools, check out the links on the next page.

Pennsylvania Office

AREAS WE SERVE
Counties
Lancaster County
York County



Zip Codes Served

17019	Dillsburg
17302	Airville
17309	Brogue
17313	Dallastown
17314	Delta
17315	Dover
17319	Etters
17321	Fawn Grove
17322	Felton
17327	Glen Rock
17329	Glenville
17331	Hanover
17339	Lewisberry
17345	Manchester
17347	Mount Wolf
17349	New Freedom
17352	New Park
17354	Porters Sideling
17356	Red Lion
17360	Seven Valleys
17361	Shrewsbury
17362	Spring Grove
17363	Stewartstown
17364	Thomasville
17365	Wellsville
17366	Windsor
17368	Wrightsville
17370	York Haven
17401	York
17402	York
17403	York
17404	York
17406	York
17407	York
17408	York

7022	Elizabethtown
17501	Akron
17502	Bainbridge
17505	Bird in Hand
17509	Christiana
17512	Columbia
17516	Conestoga
17517	Denver
17518	Drumore
17519	East Earl
17520	East Petersburg
17522	Ephrata
17527	Gap
17529	Gordonville
17532	Holtwood
17535	Kinzers
17536	Kirkwood
17538	Landisville
17540	Leola
17543	Lititz
17545	Manheim
17547	Marietta
17551	Millersville
17552	Mount Joy
17554	Mountville
17555	Narvon
17557	New Holland
17560	New Providence
17562	Paradise
17563	Peach Bottom
17565	Pequea
17566	Quarryville
17569	Reinholds
17572	Ronks
17576	Smoketown
17578	Stevens
17579	Strasburg
17581	Terre Hill
17582	Washington Boro
17584	Willow Street
17601	Lancaster
17602	Lancaster
17603	Lancaster
17611	Lancaster

Maryland Office

AREAS WE SERVE

Baltimore County (Towson 21204,21252,21284,21285,21286)
Anne Arundel County (Glen Burnie 21060,21061,21062)
Prince George’s County (Potomac 20854,20859)
Montgomery County (Rockville 20847, 20848,20849,20850,20851,20852,20853,20854,20855,)
Harford County (Bel Air 21014,21015)
Baltimore City ( 21201, 21202,21203,21204,21205,21206,21207,21208,21209,21210,21211,21212,21213,

and other areas in Maryland and Washington, D.C.

Delaware Office

AREAS WE SERVE

Counties
Sussex
New Castle
Kent

1-800-356-0484
CALL NOW FOR MORE INFORMATION ON FINGER PRINT DUST CLEAN UP. We Are Open 24 Hours Seven Days A Week

1. Call our office now at 1-800-356-0484 24 hours seven days a week in Maryland, Pennsylvania, Virginia, Washington, DC and Delaware . We never close. You can call our office and ask as many questions from our experienced staff without feeling pressured.

2. If this is not an emergency , but you have questions please email us!- Please email our company at jeff.cohn@si-restoration.com.

Who Is SI Restoration?

SI Restoration is certified by ABRA and IICRC to perform tape removal blood luminal and many other cleaning items left behind by Maryland, Delaware and Pennsylvania police and law enforcement agencies.

How Does SI Restoration Remove Finger Print Dust From Your Office And Home?


When a forensic team dusts for fingerprints, they literally throw the graphite dust onto every surface of the room (or car) being tested. The substance spreads onto both visible surfaces and nooks and crannies.  Trying to clean it yourself is futile. Water actually activates the dust, and it’s difficult to get rid of it with over-the-counter cleaning products.

Fingerprint dust can be one of the most difficult and frustrating things to clean. It is made up of a black graphite powder that you do not want to get wet. It seems to spread faster than you can clean it.