1 / 24

AUTOMOBILE GLASS

AUTOMOBILE GLASS. With Thanks To Jerry Chisum Author: “ Evidence and Crime Scene Reconstruction”. SHOOTING CAR WINDOWS. American automobiles have two types of window glass. The windshield is laminated. SHOOTING CAR WINDOWS.

jamar
Download Presentation

AUTOMOBILE GLASS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AUTOMOBILE GLASS With Thanks ToJerry ChisumAuthor:“Evidence and Crime Scene Reconstruction”

  2. SHOOTING CAR WINDOWS • American automobiles have two types of window glass. The windshield is laminated.

  3. SHOOTING CAR WINDOWS • American automobiles have two types of window glass. The windshield is laminated, the rest is stressed safety glass. Each acts differently upon breaking.

  4. Side View DID THE IMPACT COME FROM INSIDE OR OUTSIDE? When regular glass is impacted the resulting fracture spreads out as it moves away from the site of impact. Note how the angles spread outward forming a cone

  5. DID THE IMPACT COME FROM INSIDE OR OUTSIDE? With laminated glass the fracture spreads out normally, but only on the front side. Laminate spreads out the energy.

  6. POINT OF IMPACTStressed Glass • All breaks radiate from one point. • Primary lines lead to impact point.

  7. SEQUENCE OF SHOTSStressed Glass *First shot causes lines to radiate out and fracture the glass into many small pieces.

  8. SEQUENCE OF SHOTSStressed Glass *First shot causes lines to radiate out and fracture the glass into many small pieces. *Subsequent shots only break the small pieces. Only first shot can be traced.

  9. SEQUENCE OF SHOTSLaminated Glass O The first shot sends out radial lines • 2nd shot lines may over extend 1st • The shock wave, carried by the plastic causes 1st lines to grow.

  10. SEQUENCE OF SHOTSLaminated Glass O The first shot sends out radial lines • 2nd shot lines may over extend 1st • The shock wave, carried by the plastic causes 1st lines to grow. Like this...

  11. SEQUENCE OF SHOTSLaminated Glass First Shot

  12. SEQUENCE OF SHOTSLAMINATED GLASS SECOND SHOT

  13. SEQUENCE OF SHOTSLAMINATED GLASS THESHOCK WAVE EFFECT • But which shot occurred first?

  14. ? SEQUENCE OF SHOTSLAMINATED GLASS Beats me! THESHOCK WAVE EFFECT • But which shot occurred first?

  15. ? SEQUENCE OF SHOTSLAMINATED GLASS Beats me! THESHOCK WAVE EFFECT • With LAMINATED GLASS You Just Can’t Tell!

  16. ONE SIDED BREAK • LAMINATED ONLY • A “star shaped” break on only one of the glass panes may be made by striking the opposite side. • Tap a dowel with a hammer, the opposite side breaks.

  17. GLASS - VIDEO CLIPS Density Testing Density Testing + CA Hackle Marks Press Alt–Enter to view video in Full Screen Mode Press Alt–Tab to return to this slide.

  18. Let’s see if you really understand the “hackle Marks” video…you think the suspect in a case broke his own window from the OUTside of the house in order to fake a burglary.note: this is NOT the same as in the video write an “if” / “then” hypothesis showing How you can prove it using glass hackle marks. GLASS - Hackle Marks

  19. hypothesis:If the impact occurred to the glass surface on the outside of the house, GLASS - Hackle Marks then …

  20. hypothesis:If the impact occurred to the glass surface on the outside of the house, GLASS - Hackle Marks then the hackle marks would be at right angles to the glass surface on the inside of the house. OUT IN

  21. hypothesis:If the impact occurred to the glass surface on the outside of the house, RibMarks GLASS - Hackle Marks then the hackle marks would be at right angles to the glass surface on the inside of the house. OUT IN

  22. Outside Inside hypothesis:If the impact occurred to the glass surface on the outside of the house, RibMarks GLASS - Hackle Marks then the hackle marks would be at right angles to the glass surface on the inside of the house. OUT IN

  23. Outside Inside hypothesis:If the impact occurred to the glass surface on the outside of the house, RibMarks GLASS - Hackle Marks HackleMarks then the hackle marks would be at right angles to the glass surface on the inside of the house. OUT IN

  24. Outside Inside hypothesis:If the impact occurred to the glass surface on the outside of the house, RibMarks GLASS - Hackle Marks HackleMarks 90º then the hackle marks would be at right angles to the glass surface on the inside of the house. OUT IN

More Related