The 6 biggest police evidence blunders

police evidence
Don’t let poor evidence put your case on ice

Auditing evidence procedures and storage rooms is always an interesting endeavor.  Every piece of evidence in the room brings with it stories of true crime and shear amazement.  It also brings along those moments that make you say what the blank…  Here’s 5 of the recent blunders I’ve seen.  Make sure that your police department isn’t making them.

Biological evidence is thawing and leaking

Some evidence is better kept in a cool location. Cetain evidence rooms have installed refrigeration units to maintain biological evidence in well preserved state.  But when power failures occur this evidence tends to get really messy.  Just as you would with chemicals, secondary containment should be provided for all biological evidence that is going to be stored in refrigeration units.  In addition, you would be wise to install an alarm system on the refrigeration unit to warn you when temperatures drop.

Storing chemicals illegally

Just because it’s evidence, doesn’t mean it is not subject to hazardous chemical storage regulations or Cal-OSHA safety regulations.  Evidence is no longer evidence when it is in your workplace. When chemicals are being stored (think meth lab) they need to be properly stored and segregated in your evidence warehouse.  This includes secondary containment, fire cabinets and the like.  Leaving chemicals lying on the ground could lead to leaks and nearby evidence being damaged.

Left the backdoor open

I have yet to see a solitary entrance into an evidence room and I usually end up finding a way in that isn’t locked or that an unauthorized person has a key to.  If you have multiple entrances to your evidence storage room, you should ensure that all entry/exits have access control and that it works.   Otherwise, get prepared to be embarrassed when I  show you all the things I was able to obtain from your evidence room during the audit.  Missing homicide weapons are never an easy thing to explain.

Allowing officers to take a second look at their evidence

Was it $50,000 or $51,593.00 that we found in the backseat of the car?  Allowing officers to take possession of evidence after it has been placed in evidence locker raise more than just eyebrows.  Make sure that evidence placed in the locker for tagging and storage is not allowed to be taken by anyone but the property officer after it is submitted.

Using non-archival markers

Was it Mark or Martha who tagged this bloody shirt in?  Chain of custody is a serious concern and when you need to keep evidence for 20, 30 or 99 years, being able to determine that chain of custody is vitally important.  The wrong type of ink can spell, well, nothing if your not careful.  Make sure that the paper and ink that you are using has the appropriate lifespan for use in your evidence room.

Not using DNG file formats

DNG – what is it?  It is a universal file format for electronic images.  Sometimes evidence is in the form of pictures.  These pictures are archived on a CD or DVD and placed in evidence for safe keeping. The question is whether we will be able to view them in the future?  .jpg and gifs are fine so long as they are supported, but 20 years from now, we don’t know what new and improved file format will be used or supported by the major computer software.  Software seems to change daily and honestly I am impressed that .jpg and .gif is still around.


Quoted from

Raw file formats are extremely popular in digital photography workflows because they offer creative professionals greater creative control. However, cameras can use many different raw formats — the specifications for which are not publicly available — which means that not every raw file can be read by a variety of software applications. As a result, the use of these proprietary raw files as a long-term archival solution carries risk, and sharing these files across complex workflows is even more challenging.

The solution to this is Digital Negative (DNG), a publicly available archival format for the raw files generated by digital cameras. By addressing the lack of an open standard for the raw files created by individual camera models, DNG helps ensure that photographers will be able to access their files in the future.

Hundreds of software manufacturers such as Apple and Google have developed support for DNG. And respected camera manufacturers such as Leica, Casio, Ricoh, Samsung, and Pentax have introduced cameras that provide direct DNG support. Learn more ›

In addition to the Digital Negative Specification, Adobe provides the free Adobe DNG Converter (Windows | Mac OS), which easily translates raw files from many of today’s popular cameras. Software developers and manufacturers can download the complete DNG Specification (PDF, 486k) file. DNG is supported by the following software versions: Photoshop CS to Photoshop CC, Photoshop Elements 3 to Photoshop Elements 12, and all versions of Lightroom.


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