第三场讲座“世界名案分析”大纲Shooting-Investigation.ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,*,Shooting Case Investigation,Dr.Henry C.Lee,Chief Emeritus,State Police Lab,Professor,University of New Haven,Director,Forensic Research&Training Center,Type of firearms,Handguns,Rifles,Shotguns,Submachine guns,Machine guns,COMPONENTS OF A FIREARM,BARREL,Rifled or Smooth,STOCK OR GRIP,FIRING MECHANISM,Firing Pin,Breech Lock,Ejector,Extractor,LOADING MECHANISM,Single,Automatic,double barrel,MAGAZINE OR CYLINDER,AMMUNITION COMPONENTS,Projectile,Bullet,shot pellets,slug,Cartridge Case/Shell,Primer,Center v.Rim fire,Powder,Black Powder,Smokeless(Nitrocellulose base),Wad,BULLETS-PROJECTILES,CALIBER,GUAGE,SHOT SIZE,COMPOSITION,CLASS CHARACTERISTICS,MANUFACTURER,STYLE,TYPE WEAPON FIRED FROM,INDIVIDUAL CHARACTERISTICS,STRIATIONS FROM LANDS&GROOVES,CARTRIDGE CASES,MANUFACTURER,CALIBER&LOAD SPECIFICATIONS,FACTORY V.RELOAD,INDIVIDUAL CHARACTERISTICS,FIRING PIN IMPRESSION,BREECHFACE MARK,CHAMBER MARKS,EXTRACTOR/EJECTOR MARKS,WEAPON EXAMINATIONS,FUNCTIONALITY PROPER,TRIGGER PULL,TRACE/FINGERPRINTS/DNA,OWNERSHIP HISTORY,TOOL MARK COMPARISONS,TYPES,Indentations,Striations,DOCUMENTATION,Photos,Seize item,Casts,REPRODUCTION/EXEMPLARS,Suspect tool,similar surface-motion-pressure,TRACE ANALYSIS,Paint analysis,COMPARISON MICROSCOPE,NUMBER RESTORATIONS,Serial NumberRestoration,Polish surface,Apply etching acid,Shooting Incident Reconstruction,Shooter location/position determination,Victim location/position determination,Homicide/Suicide/Accidental death,Trajectory determination,Distance determination,Spatial and sequence determination,Communication with HQ,Aid victims,Locate witnesses,Secure the scene,Transfer officer involved,crowd control,Documentation of the scene,Collection of physical evidence,Initiate investigation,Information,witness,statements,Theory,Record File,scene,Laboratory results,Physical evidence,Gunshot wounds,Kinetic Energy Of A Projectile,K.E.=M V,Classification of Gunshot Wounds,Contact wounds,Near contact wounds,Intermediate Gunshot wounds,Distant wounds,Wound Evidence,Entrance wound,Abrasion Rings,Powder Soot,Power particles,Exit Wound,Trace Material,Pseudo-Powder Tattooing,Bullet Wipe,SHOT GUN INJURY PATTERN,TYPES,Contact Discharge,Close Discharge,Mid-range Discharge,Distance Discharge,Contact Discharge,Muzzle against the skin,Single and circular wound,Entrance hole approximate diameter of bore,Little or no soot on skin,Little or no burn on skin,Muzzle mark on skin,GSR in wound track,Close Range Discharge,Muzzle near skin(not a contact),Circular Wound right angle,Elliptical wound slanted angle,Nibbling/cremation around wound edge,Blackened/soot on edge of wound,Annular/distant bruising,Singeing of hair/skin,GSR around wound,Mid-range Discharge,Smoke/soot diminished 20-40cm,Muzzle to target 15cm to 2 m,Powder tattooing around wound 20-6-cm,Cremated/scalloped wound edges,One central entrance hole 1m,Satellite holes around central hole 1m,Distance Discharge,Muzzle to target -2m,No burning/soot on skin,Few GSR particles,Wad may be present 5m,Central hole diminished 6-10 m,Spread of pellets increase,Trace Evidence in Shooting Cases,Residues on Bullet and Casing,Residues along Projectile path,GSR on Hands,GSR on Clothing,GSR on Target,Blood Spatters on Body and Scene,Trace materials on Clothing,Blood,Tissues on Weapon,Trace and Transfer Evidence,Hair,Fibers,Tissues,Salvia,Bloodstains,GSR Patterns,Soil Stain,Grass Stain,GSR(Gun Shot Residue)Deposits,GSR from Muzzle,Powder Particles on Target(Body,Wound,Clothing,Object,Surfaces),GSR from Cylinder gap,GSR particles on Hands,Clothing,GUN SHOT RESIDUE,BURNED&UNBURNED POWDER PARTICLES,PRIMER RESIDUE:,LUBRICANTS,BARREL RESIDUES/TRANSFERS,PROJECTILE WIPES/TRANSFERS,Bullet Trajectory Determination,Probe,String,laser,Alignment of laser beam,Documentation of laser beam,Positioning stages,Angular information from the aligned beam,Interposition of objects in the laser beam,The use of hollow probes with laser beam,Dual-opposed co-axial laser beam,High ambient light level,auxiliary alignment target,Problems associated with shooting reconstructions,Damage to the bullet,Through and through shots,Alteration of pattern evidence,Inability to recover evidence,alteration of physical evidence,Misinterpreted information,General Consideration of Ricochet,The projectile will lose some energy,The depart is usually different than the incident angle,The projectile usually has deformation,Trace transfer evidence usually presence,Impact surface may play important role,Laws of Physics on Ricochet,The Steeper the incident angle,the greater the force acting on the bullet at impact.,The greater the impact on the bullet results the greater loss of velocity and the greater deformation to the bullet.,Important Terms,Incident Angle vs.Departure Angle,Critical Angle,Pinch Point,Bow effect&Chi sum Trail,Lead Splash vs.Lead wipe,Hard Surface vs.Soft Surface,Ricochet&Deflection,Ricochet is the continued flight of a rebounded projectile after an actual angle impact of a surface or object.,Deflection is a deviation in the projectiles normal path as a consequence of an impact.,1.As a consequence of a ricochet,2.As a consequence of a penetration,Examination of Ricochet Bullet,Bullet Deformation,Bullet Destabilization,Bullet Deflection,Bullet Ricochet Surface,1.Yielding Surface:Soil,Sand,Water,Tissue,Sheet Metal,Wood,Drywell,2.Frangible Surface:Cinder Blocks,Bricks,Stepping Stone,Procaine Surface,3.Non Yielding Surface:Stone,Concrete,Steel,Heavy Metal,Portland-A Shooting Investigation,Date:01-13-93,Time:1300 hrs,Site:Route 66w Portland,CT,Reconstruction,Based on Pattern Evidence,Based on Serological Evidence,Based on GSR Evidence,Based on Injury Patterns,Based on Trace Evidence,Based on Psychological Analysis,Based on Witness Statements,Based on Photographic Evidence,