PDA

View Full Version : Date stamp on digital camera question - please help



SecretScribe
06-13-2007, 12:22 PM
Hi there


Need help please for an important plot-point:


I have a reference in my story to a number of compromising photos that were taken and have a date/time stamp on, so the photos become an alibi for one of the suspects in the case. In my story I have one of the detectives ask the other if it is not possible that someone could have tampered with the date/time stamp and the other says that the technical people have checked it and that it has not been changed.


My questions:
- Can the date/time stamp on a digital camera be changed or tampered with?
- If it has been changed, would a technical person be able to tell?
- In other words, does my scenario work?


I really hope I have explained it all properly!


Thanks
SecretScribe

Bmwhtly
06-13-2007, 12:28 PM
If it's an actual date-stamp, that could probably be fiddled with.

If, however, it's Exif information; I don't think you can alter that and that shows date/time.

Sophia
06-13-2007, 12:39 PM
If the photos were taken intentionally to provide an alibi, then you could have the date/time stamp as required and no one could prove it had been changed, as it never would have been. Normally when you buy a digital camera, you set the time on it yourself. There may be software versions that update that time from an internet source when the camera is connected to a computer with an internet connection, but if that never happens, then the camera's internal clock can say anything.

I don't know if changing the date/time stamp afterwards would leave a 'trail' for technical people to follow, but I'd be surprised if it could: I'm guessing you'd have to allocate some of the camera's memory for the internal clock, and for it to retain previous settings, it would need to be larger than standard. But I'm just guessing, sorry.

SecretScribe
06-13-2007, 02:20 PM
If, however, it's Exif information; I don't think you can alter that and that shows date/time.

Bmwhtly - thanks for the reply, what is Exif information? :Huh:

ElaraSophia - thanks, the photos were not taken to establish an alibi, they do that inadvertently. In fact the photos are child pornography, so the person that took them is looking at a long stretch in jail. Unfortunately (for the detective) they also prove (through the date/time) that this suspect is innocent of the murder.

I just don't want someone reading this to think - what an idiot, the date and time on a camera don't prove anything!

Thanks for the help guys!!

Bmwhtly
06-13-2007, 02:26 PM
Bmwhtly - thanks for the reply, what is Exif information? :Huh: Exif (http://en.wikipedia.org/wiki/Exif)Information is data embedded in many digital photos (depending on the camera & file format) showing when it was taken and with what equipment.
Let me see if I can dig up an example. brb.

alleycat
06-13-2007, 02:28 PM
Do you want the detectives to eventually discover the time stamp is wrong? I have an idea if you do.

Puma
06-13-2007, 02:28 PM
Hi Secret - I agree that the date/time can (and are) set by the camera's owner and that there would not be a trail left to show they had been altered. It's also possible to set the camera up so the date and time don't show. I'm not sure whether the cameras are updated when they're docked on a computer. I'm also not sure whether it's possible to set the date and time back - but if that can be done, that would certainly be one of the lines of questioning that would come up in a trial. My thoughts - Puma

Bmwhtly
06-13-2007, 02:37 PM
Exif (http://en.wikipedia.org/wiki/Exif)Information is data embedded in many digital photos (depending on the camera & file format) showing when it was taken and with what equipment.
Let me see if I can dig up an example. brb.I can't find an example, but If you've got any pictures you took on your computer, open one. Right click and click on properties. On (I think the security tab) one of the tabs, it'll show all that stuff.

alleycat
06-13-2007, 02:56 PM
I can't find an example, but If you've got any pictures you took on your computer, open one. Right click and click on properties. On (I think the security tab) one of the tabs, it'll show all that stuff.
Wouldn't copying the files change that? Or would the original data still be embedded somewhere?

SecretScribe
06-13-2007, 02:59 PM
Thanks for all the help! To clarify a bit further - the detectives don't later find out that the time/date was wrong. This suspect is eliminated and it turns out at the end that the murder was in fact committed by someone else. So the date/time on the photos is correct and was never tampered with.

The problem was that when I mentioned this plot point to someone, they immediately said - but how do you know the date wasn't tampered with. And the thing is, I think many readers would have exactly this response, so I wanted to pre-empt the inevitable chorus of objections. The thing is that eliminating this suspect forces the detectives to move on to other posibilities, so the suspect needs to be eliminated. If the camera thing is a real issue, then I may have to change the plot on this point. - BIG Sigh -

Bmwhtly
06-13-2007, 02:59 PM
Wouldn't copying the files change that? Or would the original data still be embedded somewhere?As far as I can tell, the data stays embedded. Since it's part of the file as much as the pixels that make up the picture.
I can't show you an example because all the pictures here are hosted, so the only info we get is the URL.

SecretScribe
06-13-2007, 03:05 PM
Bmwhtly - if I wanted to use your suggestion, any idea how to phrase it? Could it be something like - 'We have looked at the Exif data and the photos are all from the night of the murder, spanning a time period from eleven in the evening until two the next morning.'

alleycat
06-13-2007, 03:08 PM
Thanks for all the help! To clarify a bit further - the detectives don't later find out that the time/date was wrong. This suspect is eliminated and it turns out at the end that the murder was in fact committed by someone else. So the date/time on the photos is correct and was never tampered with.

The problem was that when I mentioned this plot point to someone, they immediately said - but how do you know the date wasn't tampered with. And the thing is, I think many readers would have exactly this response, so I wanted to pre-empt the inevitable chorus of objections. The thing is that eliminating this suspect forces the detectives to move on to other posibilities, so the suspect needs to be eliminated. If the camera thing is a real issue, then I may have to change the plot on this point. - BIG Sigh -
You can have them discover that the time stamp is indeed correct. Have one of the photos show part of a newspaper or a television in the background. The detectives don't pay any attention to it as first until the issue of the time stamp come up. They are able to blow up the photo and tell by the newspaper that the photo couldn't haven't been earlier (kind of like terrorists making a hostage hold up a newspaper); or if you use the TV idea, that the show on the televison was only on at a certain time.

Bmwhtly
06-13-2007, 03:09 PM
Bmwhtly - if I wanted to use your suggestion, any idea how to phrase it? Could it be something like - 'We have looked at the Exif data and the photos are all from the night of the murder, spanning a time period from eleven in the evening until two the next morning.'If you like. Although you may want to tell your readers what exif is. If this is a trial, you could phrase it simply for the jury's benefit.
But, it's up to you.

alleycat
06-13-2007, 03:12 PM
As far as I can tell, the data stays embedded. Since it's part of the file as much as the pixels that make up the picture.
I can't show you an example because all the pictures here are hosted, so the only info we get is the URL.
I just copied a photo over; the properties show a new "created" date. Of course, there may still be something hidden; I'm no expert on the data associated with a digital camera file.

alleycat
06-13-2007, 03:13 PM
If you like. Although you may want to tell your readers what exif is. If this is a trial, you could phrase it simply for the jury's benefit.
But, it's up to you.
I would probably use something like "the file data" or "the data associated with the digital photo files" rather than throw in a technical term. Just an idea.

Bmwhtly
06-13-2007, 03:20 PM
I would probably use something like "the file data" or "the data associated with the digital photo files" rather than throw in a technical term. Just an idea.That's what i was thinking, although I lean more towards techno-babble; "Digital Tags" or something.

Now, I found an example if you like.

Take a look at this post (http://www.absolutewrite.com/forums/showpost.php?p=590757&postcount=110)from the family album:
Now, if you look at the properties of the picture, it won't tell you anything.
But, if you save it to your computer (right click, save as). Then look at the properties of the copy on your computer.
Click on the summary tab and you'll see that Exif tells us the model of camera that took it as well as the date and time it was taken.

That also answers your point, Alley. The data remains with the file.

wordmonkey
06-13-2007, 04:24 PM
Totally fake-able.

I could do it.

As long as I knew ahead of time that I was faking it and the date and time required. If we are talking premeditated, to create a specific alibi for a specific event, and I was stting it up AFTER the event, I could cover all the bases, even time specific content within the pic.

However, were I a detective, I might be a little suspicious of asomeone taking pics of themself without a bloody good reason. "Oh yeah, detective. I just happened to have my camera ou and started taking picture of myself in the mirror." would set alarmbells ringing for me.

Bmwhtly
06-13-2007, 04:32 PM
Totally fake-able.

I could do it.

As long as I knew ahead of time that I was faking it and the date and time required. And there's the point. Since the only reference point for the data is the time and date on teh camera which, i assume, can be set.

However, if the pictures are from a third party (Cop, PI, Tourist or whatever) then the data could stand.

To fake it, you need to know ahead of time. And even setting the wrong date, you'd still need to be careful you don't catch, for example, the wrong days newspaper in the shot. Not all that easy if it's a public shot.

SecretScribe
06-13-2007, 04:40 PM
Wordmonkey - if you did this, would a tech-savvy person be able to track the change, or somehow figure out that the change had been made?

Thing is, in this case, the photos themselves are incriminating, but for a different crime (child porno). The suspect would not have changed the date and time on the photos in order to get out of the murder charge, and thereby incriminate himself anyway. So the issue is just that I don't want to put something in my story that will cause a techie reader to shout - 'but they could have changed this!' - and therefore stop believing in my plot.

MidnightMuse
06-13-2007, 06:21 PM
But is your suspect a techie? I have two digital cameras. Both are Kodak, but on one I can alter, or completely remove the time/date stamp. On the other, it's embedded in the files and can't go away unless I make copies of the photos and fiddle.

The average Joe doesn't bother with this stuff, wouldn't know you could change it and wouldn't even realize it's there.

SecretScribe
06-13-2007, 06:53 PM
The average Joe doesn't bother with this stuff, wouldn't know you could change it and wouldn't even realize it's there.


I think these guys are pretty average Joes and wouldn't know how to change this.

SecretScribe
06-13-2007, 06:57 PM
:D Thank you all so much for the help!!!

wordmonkey
06-13-2007, 10:07 PM
Wordmonkey - if you did this, would a tech-savvy person be able to track the change, or somehow figure out that the change had been made?

I'm not sure. The way I would do it, would be to reset the dates on the camera AND computer. That way, when I sinc them up, the file creation date would match on both machines. That's the simplest. I could go inot photoshop and edit it too, but the dates would be the simplest.

Now I'm sure some tech-wiz would be able to take the backend coding apart and see that the date had been changed. So I would err on the side of caution and say yes, a serious techie could work out it was a fake.

But in theory, from what you said, your photo evidence actually would lead the cops to verify the suspects alibi and while he might be guilty of something else, that would eliminate him in that investigation, so they wouldn't need to look further and you would be good to go.

As far as tech people pointing out errors, Dan Brown has a screamingly obvious techie flaw in "Angels and Demons" that would have resolved the entire "ticking clock" plot in mere seconds. The sales I suspect were enough that he didn't sweat the odd letter from a tech savvy person saying, "Hey, why didn't they just do this and find the bomb?"

(Note: It wasn't a bomb, so I didn't spoil it for anyone!) :D

Tsu Dho Nimh
06-14-2007, 11:30 PM
All you have to do is set the date on the camera to what you want and take the pictures.

EXCIF data is editable.

Editing the date and time on the image might leave traces of editing in the pixels.

wordmonkey
06-15-2007, 12:01 AM
Editing the date and time on the image might leave traces of editing in the pixels.

Not if you're good. :D

Actually, yeah, but that would take time and real analysis. And, as I said, if I were really setting this up, I could ensure it was as water-tight as possible.

The safest way to cover myself would be to take the pics and just print them. Once that's done, if I erased the memory (I mean complete wipe, not just delete as that would make the image salvagable), you'd only have the hard-copy with the date. And if I also did some photoshop work, I know I'm good enough to make it so an expert couldn't tell (that sounds pretty arrogant, but having working in design and advertising for many years, I've told some pretty convincing visual lies with the aid of photoshop).