Why verify?

The importance of verifying digital video evidence before leaving the scene.

The characters and crimes in this story are fictitious, but the DVR is real.  Everything the DVR does is real, as are all the photos. 

March 17, 1840 hours: A criminal robs a convenience store.

March 17, 1930 hours: Detective Murphy arrives on scene. He learns the perpetrator was armed with just a stick, but still took away a good amount of cash.

Murphy interviews Julie, the store's attendant. After interviewing Julie, he asks about the store's video surveillance system. Julie points to a door. "It's in the office. It's locked," she says, wiping tears. "You'll have to call the owner." Then she points to a phone number taped to the cash register.

"Thank you," Detecitve Murphy replies, stepping toward the office door as he pulls out his phone. Through a small window of the door he sees his objective: the digital video recorder.

March 17, 2020 hours: The store owner arrives and introduces himself as George Gupta. George explains that he's fed up with robberies in his stores and he'll do anything to help. He goes through the menus of the DVR and finds an option to copy the video to the CD/DVD drive in the DVR. Detective Murphy asks George for a ten-minute video surrounding the two minutes of the robbery.

George takes a blank CD-R from a desk drawer and puts it into the DVR. The copy starts at 0%. About fifteen minutes later the copy finishes.

Detective Murphy once learned a hard lesson: Technology is nowhere near perfect. A DVR can burn a bad CD or not burn the CD at all. So Murphy always checks the CD to see if it has anything on it. He takes the CD out of the DVR and flips it over. He tilts it in different directions. At just the right angle he sees that the CD has information burned on it. Murphy thanks George and leaves.

A week later... March 24, 1610 hours: There's been another robbery, this time a shooting involved. And a dead victim.

March 24, 1640 hours: The Lieutenant in charge comes looking for insight. "Murphy, we think this recent homicide may be connected to the robbery you're working from last week. We need to take a look at the video you got."

"Give me a few minutes to pull it up Lieutenant. I've been busy with other cases and haven't had a chance to look at it yet."

Murphy throws the CD into his computer and opens the Windows file explorer. Blank. He closes the window and opens it again. Blank. Again. Crap. What's going on?

Murphy walks the CD over to his long-time crime-fighting cohort, Detective Williams. "Williams, see if this CD has files on it."

"You're computer's better than mine," Williams says.

"Just check it for me."

They stare at Williams' computer screen. Blank. No files.

"Crap, I'm in trouble," Murphy says and he explains the situation to Williams. "You're going to have to go get another copy of the video," Williams says.

March 24, 1700 hours: Murphy calls the store owner, George.

"Mr. Gupta, this is Detective Murphy. I was at one of your stores last week and got a copy of video after a robbery. We had a look at the video CD you burned for me and didn't see any files on it. I'd like to come back over get another copy. Can you meet me?"

"The DVR only holds a week of video," George responded over the phone. "What day was that robbery?"

Murphy looked at the CD. "It was the 17th, Wednesday."

"Today is Wednesday," said George. "I remember the robbery was in the evening do you know what time?"

"Six-forty," Murphy answered.

"It's four-forty. We only have about two hours to get the video," said George.

"Can you meet us ASAP, George?"


"Thanks," Detective Murphy signed off.

This time Murphy prepares by grabbing the department's video evidence recovery kit. It's loaded with all types of collection media and a laptop so Murphy can verify the evidence at the scene.

March 24, 1735 hours: Murphy arrives on scene. George has already setup the copy process for the video. Murphy opens his recovery kit.

Murphy takes out an CD-R labeled for evidence. "Let's try again," Murphy says. "Maybe it just didn't burn right last time."

The DVR seems to write fine -- 100%. This time Murphy puts the CD into the laptop right away to check the files.

No files. Again. Man this is getting old.

March 24, 1800 hours: Murphy feels tense. Fighting technology is almost harder than fighting criminals.

"What now?" George asks. "We only have about forty minutes left until it erases."

"Let's try the format option we saw," Murphy says.

George navigates to the menu with the format option and tries to format the CD. The screen displays a foul-spelled message: "FORMATT CD-R MEDIAE WAIT". Then another message from the screen: "FAIL".

How could it fail? From the catacombs of Murphy's mind comes an insight. He recalls from a video recovery training class, if one type of disc doesn't work try another.

March 24, 1810 hours: Murphy grabs a CD-RW and they set up the copy. "INSERT A COMPATIBLE MEDIA," the DVR tells them.

March 24, 1815 hours: "Fine," Murphy says. "How about DVDs?" Murphy loads a DVD disc. George starts the copy. The response: "DVD-R IS NOT SUPPORTED".

Only fifteen minutes left to get the copy... March 24, 1820 hours: Murphy looks at the last type of disc in the kit: DVD-RW. George presses the eject button. Murphy lays the DVD on the tray. "Please," he mutters. George starts the copy. Murphy shifts his weight, staring intently at the screen.

The screen flickers. "COPYING( 0%)" But Murphy knows not to get too excited. It could be creating a blank again.

March 24, 1835 hours: The copy finishes.

Murphy moves the disc from the DVR to the laptop. He clicks and opens the Windows file explorer.

"Yes!" Murphy bursts out. "Yes! Thank you. Thank you. We got it."

March 24, 1840 hours: As the video of the crime is overwritten on the DVR, Murphy verifies the evidence on the laptop. The quality of the video evidence is good. He copies the files to the laptop's hard drive and burns a backup DVD of the evidence. George offers a drink. Murphy thanks him and walks to the convenience store's wall of coolers.


Learn about StarWitness video evidence recovery tools at StarWitnessFieldAgent.com.

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