Skid marks and laser scanner question

Discuss all Forensics & CSI related issues here.

Skid marks and laser scanner question

Postby PDePoister » Fri Mar 10, 2017 5:51 am

I've recently been asked about how to capture skid marks using a FARO Focus3D X330 HDR laser scanner. I have not had the opportunity to try this out with our scanner as we are a crime scene unit. But, we will soon be scanning traffic scenes and I need to know if anyone has any techniques to make skid marks stand out on the pavement. Keep in mind that it rains a lot here and often we are working in the dark so there will be no color information.

Are there special targets that we can use? Does paint show up in the scan? Should I just use evidence markers? Any ideas?

Thanks in advance!

Paul
PDePoister
I have made <0 posts
I have made <0 posts
 
Posts: 8
Joined: Mon Aug 29, 2016 5:57 pm
Full Name: Paul DePoister
Company Details: Tacoma Police Department
Company Position Title: Forensic Services Supervisor
Country: United States
Linkedin Profile: Yes

Re: Skid marks and laser scanner question

Postby KDersch » Fri Mar 10, 2017 12:25 pm

Even with color scans, I have ran into issues in congested mechanical settings where changing the color intensity in ReCap allowed certain features to stand out more than they did in a color view - might be something to look into...
KDersch
I have made 50-60 posts
I have made 50-60 posts
 
Posts: 50
Joined: Wed Jun 01, 2016 11:54 am
Full Name: Kyle Dersch
Company Details: Matix Technologies
Company Position Title: Engineer
Country: USA
Skype Name: kddersch@matrixti.com
Linkedin Profile: Yes

Re: Skid marks and laser scanner question

Postby dcacioppo » Sun Mar 12, 2017 4:18 am

I do not have the HDR scanner but we have used tent markers or small cones to mark the path of the skid marks for our X330. We also paint the marks before scanning. The paint will show in the scan with color, I have not tried it without color. Fluorescent Pink,
Fluorescent Orange, and White paints have worked well so far.
dcacioppo
I have made 10-20 posts
I have made 10-20 posts
 
Posts: 10
Joined: Fri Nov 20, 2015 12:08 am
Full Name: David Cacioppo
Company Details: Park Ridge Police Department
Company Position Title: Forensic Technician
Country: USA
Linkedin Profile: No

Re: Skid marks and laser scanner question

Postby colhum1 » Sun Mar 12, 2017 3:34 pm

I've recently been asked about how to capture skid marks using a FARO Focus3D X330 HDR laser scanner. I have not had the opportunity to try this out with our scanner as we are a crime scene unit. But, we will soon be scanning traffic scenes and I need to know if anyone has any techniques to make skid marks stand out on the pavement. Keep in mind that it rains a lot here and often we are working in the dark so there will be no color information.

Are there special targets that we can use? Does paint show up in the scan? Should I just use evidence markers? Any ideas?

Thanks in advance!

Paul[/quote]

Hi Paul,

We always identify our marks using road paint, primarily to show up in our photographs.
Paint is really good for identification with scans too...however...colours show up differently depending on how you view your scans.
These are all from the Faro x330.

This example shows how paint shows up with the Leica C10:

C10 Road Paint.png


here are a few examples:

Screenshot_1.jpg


Screenshot_1A.jpg


Screenshot_1B.jpg


Screenshot_1C.jpg


Screenshot_2.jpg


Screenshot_3.road.jpg


Screenshot_4.services.jpg


Screenshot_4A.services.jpg
You do not have the required permissions to view the files attached to this post.
"Just leave me alone. I know what I am doing" - Kimi Räikkönen
User avatar
colhum1
V.I.P Member
V.I.P Member
 
Posts: 441
Joined: Mon Jul 16, 2012 3:10 pm
Location: Rugby
Full Name: Colin Humphreys
Company Details: Warwickshire Police
Company Position Title: Forensic Collision Investigator
Country: UK
Skype Name: col.humphreys
Linkedin Profile: Yes

Re: Skid marks and laser scanner question

Postby PDePoister » Sun Mar 12, 2017 8:19 pm

Thanks for the examples. I'm surprised at how well the skids actually show up in the scans. But, I definitely like the paint results. I'll have to do a paint test to make sure what we're using shows up well too.

Where did you get those little spheres? I really like those.

Thanks again for your help!

Paul
PDePoister
I have made <0 posts
I have made <0 posts
 
Posts: 8
Joined: Mon Aug 29, 2016 5:57 pm
Full Name: Paul DePoister
Company Details: Tacoma Police Department
Company Position Title: Forensic Services Supervisor
Country: United States
Linkedin Profile: Yes

Re: Skid marks and laser scanner question

Postby dcacioppo » Sun Mar 12, 2017 11:50 pm

We use koppa tarets. They have all different sizes. Talk to Tad and he can help you choose what you need. Otherwise if you are ambitious you can make your own targets out of ornaments, styrofoam balls, glass globes, etc. You can search 'Home made spheres - accuracy' on this blog as well.

http://www.koppatargets.com
dcacioppo
I have made 10-20 posts
I have made 10-20 posts
 
Posts: 10
Joined: Fri Nov 20, 2015 12:08 am
Full Name: David Cacioppo
Company Details: Park Ridge Police Department
Company Position Title: Forensic Technician
Country: USA
Linkedin Profile: No

Re: Skid marks and laser scanner question

Postby ClarkCoSheriff » Mon Mar 13, 2017 2:09 pm

The paint will show up great when you scan without color. It will provide great contrast, even in the dark. Here are some shots from an Officer-Involved Shooting we investigated in a rural part of another county. Because the lighting was so poor at the scene, I chose not to use any light at all in order to avoid the funky color and shadow effects from too little lighting. Here is one of the point cloud:

Paint Mark.jpg


And another from Quick view:

Paint Mark 3.jpg


Regarding skid marks when it is wet, I have not tried this as I don't normally scan crashes either. However, I have also thought of the idea previously mentioned of using a marker such as a number placard or a small sphere to mark the beginning, end and points in the middle of the skid mark. Hope this helps.
You do not have the required permissions to view the files attached to this post.
Joe Swenson
Clark County Sheriff's Office
Major Crimes Unit
User avatar
ClarkCoSheriff
I have made 30-40 posts
I have made 30-40 posts
 
Posts: 36
Joined: Tue Jul 29, 2014 6:16 pm
Full Name: Joe Swenson
Company Details: Clark County Sheriffs Office
Company Position Title: Detective
Country: USA
Linkedin Profile: No

Re: Skid marks and laser scanner question

Postby Formula1982 » Tue Mar 14, 2017 12:59 pm

If it were myself tackling this, the first thing i'd want to know is how accurate do you need the skid marks?
Maybe scanning them wouldn't be enough to define exactly where they start and stop, which is what I assume you need quite accurately picked up for your needs. I'd consider putting down some white tape adjacent to the extents of the skid mark which should be picked up clearly by the scanner and allow you to define it in the resultant data.

I doubt a camera even with good lighting would be able to pick up the skid in a satisfactory way.

I've scanned alot of race circuits at night and it picked up the skid marks very clearly, just from the intensity values of the data. Skid marks tend to have a much lower reflectance than the surrounding asphalt.
Formula1982
I have made 20-30 posts
I have made 20-30 posts
 
Posts: 29
Joined: Tue Oct 13, 2015 4:02 pm
Full Name: Stephen Ferrari
Company Details: UTEC StarNet
Company Position Title: UTEC StarNet
Country: United Kingdom

Re: Skid marks and laser scanner question

Postby PDePoister » Thu Mar 16, 2017 2:31 am

Thank you all for the replies. It sounds like there are a couple different solutions to try. I think the next step is to go out and take some scans to try these ideas out. I'm especially interested to see what happens when the pavement is wet.

Thanks again!

Paul
PDePoister
I have made <0 posts
I have made <0 posts
 
Posts: 8
Joined: Mon Aug 29, 2016 5:57 pm
Full Name: Paul DePoister
Company Details: Tacoma Police Department
Company Position Title: Forensic Services Supervisor
Country: United States
Linkedin Profile: Yes

Re: Skid marks and laser scanner question

Postby kastopek » Thu Mar 16, 2017 6:58 pm

Good Afternoon,

We have scanned thousands of scenes involving a lot of evidence in different forms. (skids, gouges, scrapes, furrows, etc.) One thing I can tell you is you can never have enough scans out on the roadway. We always paint, unless the roadway "mainly interstate" is too dangerous (in that case we might back ourselves up and shoot evidence and a few common points with total station). Attached is our own color test we ran in color and black and white. Also, if your skids are going off the pavement and leaving furrows I suggest putting different colored ground stakes in to make them show up better. Do not use flags as the scanner pics up on it moving in the mind. If I can be of better help or you have other question send me an email and I will be glad to help.
You do not have the required permissions to view the files attached to this post.
Thanks,

Kyle Stopek
Collision Specialists, Inc
625 Green Street
Gainesville, GA 30501
1-855-CSI- 6776 Toll Free
770-287-8734 Office
770-287-8688 Fax
kstopek@collisionspecialistsinc.com
www.collisionspecialistsinc.com
User avatar
kastopek
I have made 10-20 posts
I have made 10-20 posts
 
Posts: 12
Joined: Thu Dec 11, 2014 3:18 pm
Full Name: Kyle Stopek
Company Details: Collision Specialists Inc
Company Position Title: 3D and CAD
Country: United States
Linkedin Profile: Yes


Return to Forensics & CSI

Who is online

Users browsing this forum: No registered users and 1 guest

 
SiteLock

Stay in touch    RSS feed    Twitter    Youtube    Linkedin

LSF SPONSOR

Accessibility | Terms of Use | Privacy Policy
DouZa Webdesign