Recovering a laptop from a river.
Here is one of the stories that I have to be very careful with, I can tell you what happened, just not who the story is about.
One of the groups I dealt with while running the lab in Stuttgart was the diplomatic group. They dealt with all kinds of agencies in Africa, one being law enforcement. The Uganda police reached out to see if they could help with a problem, and it came to my desk. It was a laptop computer that had been tossed into a river as a bad person 
was fleeing from the Ugandan police. They wanted to know if my team could get any information off of it.
Myself and one other team member had gone through a class and were certified in hard drive recovery. So the diplomatic guys told the Ugandan police “Sure! We can get stuff back.” I do so love it when someone else writes a verbal check I now have to cash. Did the sarcasm come through in that last sentence?
When a drive has been in water the first rule is to keep it wet. Which they didn’t do. Now our job was order of magnitudes harder. In case you didn’t know, hard drives are not water proof. All the things that reside in the water in that Uganda river were now dried onto the disk itself.
The process is that we had to find as close a match to the original drive as possible, and get one or two if we can. This meant scouring Ebay and other used drive sources for what we needed. This took a few weeks. Then we had to take the original drive completely apart. The disk itself we put into an ultrasonic cleaner, just like the one you see being used on jewelry. When the water turned a color, we drained and cleaned the unit, refilled it with clean distilled water and ran it again. Usually for an hour at a time. We did this for over a week.
Then we took the disk out of one of the donor drives and put the cleaned disk in. Using a very special device known as a PC3000 which allows you to control a disk at any level you want, we fired the drive up and thankfully the drive gods were on our side. The drive mounted and we started to pull the data off.
We got about 90% of the data back, except for the areas that were sitting under the heads while in the river. Those places rusted beyond repair. We had to read right up to the bad spots and then just the other side. This can be a very time consuming process to say the least. But then most of forensic work takes a lot longer than people expect, which is the result of all the TV shows that get DNA back in a couple of minutes.
We sent the data back to Uganda, and the end result was that the bad guy was fully convicted and sentenced. It was one of the most satisfying cases I worked on while at the lab. Certainly one of the hardest.
For the record, I hope I don’t have to do that level of recovery again.