NYCLAC Report Standardization Project
- Unique case identifier on each page of report (such as lab number)
- Title of the report (such as “report of laboratory analysis”)
- Identification of the laboratory
- Requesting Agency Info or at a minimum requesting agency
- List or explanation of items examined
- General indication of methodology utilized
- Date report issued
- Signature and title of examiner (or electronic equivalent)
- Pagination of the report (example page 1 of 2 etc.)
- Statement regarding the report does not constitute the entire case file or equivalent
- Statement that definitions of terms used in the report can be located at the DCJS website and if applicable on the laboratory website or attached to report
The following items indicated a positive reaction for the presumptive presence of blood/semen.
The following items indicated a negative reaction for the presumptive presence of blood/semen.
The following items were inconclusive for the presumptive presence of blood/semen (state reason).
Specific observations defined and any sources of information used to draw conclusions.
Statements made based on observations or other information provided.
An L-shaped piece of plastic used in photography that is marked with circles, black and white bars, and 18-percent gray bars to assist in distortion compensation and provide exposure determination. For measurement, the plastic piece is marked in millimeters.
A small blood drop produced as a by-product of drop formation.
A bloodstain with characteristics that indicate a physical change has occurred.
Alternate Light Source
A high powered light source that can control specific wavelengths and/or wavelength ranges of light, to be used for the visualization/localization of possible testing areas.
Angle of Impact
The acute angle (alpha), relative to the plane of a target, at which a blood drop strikes the target.
Area of Convergence
The area containing the intersections generated by lines drawn through the long axes of individual stains that indicates in two dimensions the location of the blood source.
Area of Origin
The three-dimensional location from which spatter originated.
A bloodstain pattern resulting from blood drops that traveled in the opposite direction of the external force applied; associated with an entrance wound created by a projectile.
A container for materials that have been exposed to blood or other biological fluids and have the potential to be contaminated with hepatitis, AIDS, or other viruses.
Fluids that have human or animal origin, most commonly encountered at crime scenes (e.g., blood, mucus, perspiration, saliva, semen, vaginal fluid, urine).
A gelatinous mass formed by a complex mechanism involving red blood cells, fibrinogen, platelets, and other clotting factors.
A deposit of blood on a surface.
A grouping or distribution of bloodstains that indicates through regular or repetitive form, order, or arrangement the manner in which the pattern was deposited.
Bloodstain Pattern Analysis
The analysis of the distribution patterns/stains at a scene resulting from the shedding of blood. Assessment of their size, shape, and distribution can help provide information as to pattern identity, as well as the possible mechanism of their formation. A useful investigative/reconstructive aid that is often incorporated into crime scene reconstructions.
An outline within a bloodstain resulting from air in the blood.
Cast / Casting
A collection procedure often utilized with impression evidence (i.e., footwear). It provides a 3-dimensional real image representation of the impression.
A bloodstain pattern resulting from blood drops released from an object due to its motion.
Cessation Cast-off Pattern
A bloodstain pattern resulting from blood drops released from an object due to its rapid deceleration.
The use of chemicals that react with specific types of evidence (e.g., blood, semen, lead, fingerprints) in order to aid in the detection and/or documentation of evidence that may be difficult to see.
The emission of light (luminescence), as the result of a chemical reaction.
Collection / Preservation
The process of securing and protecting those items documented/obtained from the crime scene. Often these methods are evidence specific, with certain methods/requirements to ensure optimal safeguarding of the item(s) in question.
A generic term used to describe physical material/evidence discovered at crime scenes that may be compared with samples from persons, tools, and physical locations. Comparison samples may be from either an unknown/questioned or a known source.
Samples whose source is unknown/questioned are of three basic types:
- Recovered crime scene samples whose source is in question (e.g., evidence left by suspects, victims).
- Questioned evidence that may have been transferred to an offender during the commission of the crime and taken away by him or her. Such questioned evidence can be compared with evidence of a known source and can thereby be associated/linked to a person/vehicle/tool of a crime.
- Evidence of an unknown/questioned source recovered from several crime scenes may also be used to associate multiple offenses that were committed by the same person and/or with the same tool or weapon.
Samples whose source is known are of three basic types:
- A standard/reference sample is material of a verifiable/documented source which, when compared with evidence of an unknown source, shows an association or linkage between an offender, crime scene, and/or victim (e.g., a carpet cutting taken from a location suspected as the point of transfer for comparison with the fibers recovered from the suspect’s shoes, a sample of paint removed from a suspect vehicle to be compared with paint found on a victim’s vehicle following an accident, or a sample of the suspect’s and/or victim’s blood submitted for comparison with a bloodstained shirt recovered as evidence).
- A control/blank sample is material of a known source that presumably was uncontaminated during the commission of the crime (e.g., a sample to be used in laboratory testing to ensure that the surface on which the sample is deposited does not interfere with testing. For example, when a bloodstain is collected from a carpet, a segment of unstained carpet must be collected for use as a blank or elimination sample).
- An elimination sample is one of known source taken from a person who had lawful access to the scene (e.g., fingerprints from occupants, tire tread impressions from police vehicles, footwear impressions from emergency medical personnel) to be used for comparison with evidence of the same type.
The unwanted transfer of material from another source to a piece of physical evidence.
Control / Blank Sample
See comparison samples.
Any location(s)/area(s) determined to have been associated with the commission of a crime.
Crime Scene Processing
The identification, documentation, collection, and/or interpretation of evidence/data at a crime scene.
Crime Scene Reconstruction
A process incorporating the data/information associated with a case in an attempt to provide a description/picture of the event(s) that transpired. The material utilized can be in the form of crime scene observations, measurements, results of analyses, autopsy reports, police reports, trajectory analysis, bloodstain pattern analysis, etc.
The characteristic of a bloodstain that indicates the direction blood was moving at the time of deposition.
The angle (gamma) between the long axis of a spatter stain and a defined reference line on the target.
The recording of information/data at crime scenes. Forms of documentation may include, but are not limited to, notes, photography, video, sketches, measurements, analysis/testing results, etc.
A bloodstain pattern resulting from a liquid that dripped into another liquid, at least one of which was blood.
A bloodstain resulting from a falling drop that formed due to gravity.
A bloodstain pattern resulting from the movement of a source of drip stains between two points.
A physical feature of the periphery of a bloodstain.
See comparison samples.
Treatment processes that can bring out additional detail(s) in the evidence. Often utilized with forms of impression evidence such as footwear.
Examination / Comparison Quality Photographs
These are images captured in a manner that allows for their use for comparison/measurement purposes.
A bloodstain pattern resulting from blood forced by airflow out of the nose, mouth, or a wound.
A bloodstain pattern resulting from the movement of a volume of blood on a surface due to gravity or movement of the target.
To produce, undergo, or exhibit fluorescence.
Forward Spatter Pattern
A bloodstain pattern resulting from blood drops that traveled in the same direction as the impact force.
Adhesive pads with a clear plastic sheet cover. Used in the collection of trace/impression evidence. The collected item(s) are placed onto the adhesive sheet, securing them to the pad.
A bloodstain pattern resulting from an object striking liquid blood.
Objects or materials that have retained the characteristics of other objects that have been physically pressed against them.
A bloodstain resulting from insect activity.
See comparison samples.
A print impression not readily visible, made by contact of the hands or feet with a surface resulting in the transfer of materials from the skin to that surface.
An object showing standard units of length (e.g., ruler) used in photographic documentation of an item of evidence.
A bloodstain pattern resulting from blood reduced to a spray of micro-drops as a result of the force applied.
Two or more physical locations of evidence associated with a crime (e.g., in a crime of personal violence, evidence may be found at the location of the assault and also on the person and clothing of the victim/assailant, the victim’s/assailant’s vehicle, and locations the victim/assailant frequents and resides).
A bloodstain from which a satellite stain originated.
An altered stain that consists of the peripheral characteristics of the original stain.
Personal Protective Equipment (PPE)
Articles such as disposable gloves, masks, and eye protection that are utilized to provide a barrier to keep biological or chemical hazards from contacting the skin, eyes, and mucous membranes and to avoid contamination of the crime scene.
A stain resulting from an accumulation of liquid on a surface.
A chemical test that provides a simple, quick way in which to effectively screen an area/item for the possible presence or absence of a material, i.e., blood. Different types of evidence require different types of presumptive tests.
A bloodstain pattern resulting from the ejection of a volume of blood under pressure.
A smaller bloodstain that originated during the formation of the parent stain as a result of blood impacting a surface.
A bloodstain resulting from the accumulation of liquid blood in an absorbent material.
The stain resulting from the liquid portion of blood (serum) that separates during coagulation.
Items that will be used only once to collect evidence, such as biological samples, then discarded to minimize contamination (e.g., tweezers, scalpel blades, droppers).
During processing these are often represented as hand drawn schematics depicting items observed at the scene, as well as their spatial relationship(s) to each other. Usually accompanied by a series of measurements accounting for the dimensions of the scene(s) and the items contained therein.
A bloodstain resulting from a blood drop dispersed through the air due to an external force applied to a source of liquid blood.
A bloodstain pattern resulting from a volume of liquid blood that falls or spills onto a surface.
Standard / Reference Sample
See comparison samples.
A bloodstain pattern resulting from the transfer of blood from a blood-bearing surface onto another surface, with characteristics that indicate relative motion between the two surfaces.
The use of adhesive tape strips to collect trace evidence. The application of the strip(s) to the area(s) of interest collects any trace evidence items present.
A surface onto which blood has been deposited.
Physical evidence that results from the transfer of small quantities of materials (e.g., hair, textile fibers, paint chips, glass fragments, gunshot residue particles).
The utilization of bullet holes, bullet impact marks, ricochet marks, etc., to help determine the possible pathway(s) associated with shots fired. Analysis can be used to help establish the possible position(s) of the shooter(s) and/or victim(s). A useful investigative/reconstructive aid that is often incorporated into crime scene reconstructions.
A bloodstain resulting from contact between a blood-bearing surface and another surface.
Unknown / Questioned
See comparison samples.
A collection method for trace evidence. Use of a vacuum apparatus allows for effective trace evidence collection over larger areas.
An absence of blood in an otherwise continuous bloodstain or bloodstain pattern.
An initial assessment conducted by carefully walking through the scene to evaluate the situation, recognize potential evidence, and determine resources required. Also, a final survey conducted to ensure the scene has been effectively and completely processed.
An altered bloodstain pattern resulting from an object moving through a preexisting wet bloodstain.
 DOJ. "Crime Scene Investigation: A Guide for Law Enforcement." (2000). Web. <https://www.ncjrs.gov/pdffiles1/nij/178280.pdf>.
 FBI. "Scientific Working Group on Bloodstain Pattern Analysis: Recommended Terminology." Forensic Science Communications. 11. 2 (2009). Web. <http://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/april2009/standards/2009_04_standards01.htm>.