Securing Digital Evidence in a Water Emergency
Water and electrical devices do not mix, especially if the device contains valuable data. When you’re on scene in a water emergency, the decisions you make in handling potential digital evidence can have huge impacts down the line in your department’s ability to recover evidence and use it to make a case. We’d like to share a few on-scene tips to help protect digital evidence that may be damaged by water.
How Water Damages Electronic Devices
Before we talk about what to do with a device in water, it helps to understand the two most common ways that water actually damages electronic devices.
Water is rarely pure water. It contains dissolved electrolytes, such as sodium chloride (table salt). Pure water is a very poor conductor of electricity, but when it contains ions (sodium and chloride), it can act as a good conductor of electricity. So, if this ion-filled water commonly known as tap, coastal, lake, river, or sewage water comes into contact with any electronic device in an ON state, it is going to make connections in places where there should be no connections. This can result in a large current, which in turn, damages the circuit.
Corrosion is another problem when water is involved with electronic devices. Corrosion happens when you have long-term exposure to water. The electrical connections within electronic devices are made of metal. When that metal comes into contact with water, it starts corroding and converting to another non-conducting compound. The additional ions that water contains can speed up this process of corrosion. If the metal connection between two parts of a circuit is sufficiently corroded, the connection is broken and the electronic device stops working.
What To Do On Scene
The decisions you make on scene in a water emergency can have significant impacts on your department’s ability to recover and analyze digital evidence for future use. We recommend the following steps to help protect the integrity of digital evidence in a water emergency:
1) Assume The Device Was Powered On
Technically, it matters whether a device is in the ON state of OFF state when disaster strikes. If the device is in its OFF state, it is very possible that it will start working as long as you dry and clean it up sufficiently before turning it on, as the dried water can no longer make any undesired connections. This can be done using rice, solvent, or other methods that will absorb or displace the water content without leaving anything to interfere with the circuit.
Unfortunately, when most disasters or accidents strike, devices found are in an unknown state. It is unknown if the device was originally in the OFF or ON state. The most conservative approach from a data recovery perspective is to assume the device was ON and has short-circuited.
2) If It’s Dry, Keep It Dry
This may sound obvious, but even a good-intentioned effort to wipe down a device with a damp cloth can do permanent damage. If a digital device has dried after a flood, storm or fire, it’s best to keep it dry. Simply get the device as it is to your digital crime lab and make sure they know it may have water damage. If there are contaminants on or inside the media, an accredited crime lab will follow specific protocols when recovering data to address any potential contaminants.
3) If It’s Wet, Keep it Wet
If the device is still wet, DON’T TRY TO DRY IT! Trying to dry a wet electronic device on scene is usually done with the best of intentions, but it’s a mistake from a data recovery perspective. As noted above, it’s not the actual water that does the damage, but the ions and contaminants in the water. If you try to dry the device you may be ensuring that those ions stay in places they shouldn’t be. The most conservative approach is to package the media with a wet towel and immediately send it to the digital crime lab.
4) If It’s Submerged, Keep It Submerged (In Distilled Water)
In a flood emergency, you may find digital devices that are completely submerged. In this situation, don’t try to dry the device. Instead, place the device in a bucket of distilled water and get it to a digital crime lab. Remember that it’s the extra ions from things like salt or other contaminants in the water that damage the device, not the water itself. Distilled water is, by definition, pure water that doesn’t contain the additional ions that can do damage.
It sounds counterintuitive to bring water to a flooded crime scene, but if you need to secure digital evidence during a flood emergency, a few gallons of distilled water could help you make the case.
If you need help recovering digital evidence that may have water damage, contact Flashback Data. We’ve worked with devices damaged by hurricanes, floods, fires and sabotage. We are the first private crime lab accredited under the same specifications as the FBI and state labs. We can help you prepare, recover, analyze and use digital evidence especially in unique and time-sensitive cases.