Technology is not a magical solution to all of the world's problems. Some hard things are hard because they require social or economic activity at absolutely massive scales.
EDIT: Followup.
Since its creation in 2002, the International Criminal Court has only convicted one person...The lack of reliable evidence is a primary limiting factor in the ability to successfully bring cases to both national and international courts.
That's is such a bald-faced misrepresentation that it is close to being an outright lie. The ICC is the outgrowth of the Interntional Criminal Tribunals which prosecuted warcrimes in Rwanda, Somalia, Bosnia, etc. Prior to the formation of the ICC, each atrocity (or set of atrocities) required the formation of a special-purpose tribunal created to prosecute those war crimes.
_The ICC does not have jurisdiction over warcrimes or other atrocities committed prior to July 1, 2002_. Moreover, due to the interference of Russia, China and the U.S., it does not have jurisdiction over crimes committed by citizens of non-signatory states (such as Russia, China, the U.S., or India) unless case is referred to it by the U.N.
The ICC currently in the process of investigating atrocities in 7 nations in Africa (including Congo and Sudan), none of which are signatories to the ICC Treaty. The cases had to be referred to the ICC by the UN, overcomming resistance by Russia and China.
Like most felony cases in Western nations, ICC cases take time. It's not a matter of inefficiency, it's a matter of collecting the overwhelming amounts of evidence that go hand in hand with the callous murders of hundreds and thousands of people.
1) The financing, arming, and coordination of atrocity perpetrators are too-often enabled through the activities of third parties such as multinational companies or financial institutions.
We already know who they are. We didn't need technology to discover this. Decades-old securities regulations pre-dating WWII sufficed.
2. In the aftermath of an atrocity, one common deficit is the availability of authentic and relevant evidence against the perpetrators. This documentation – including establishing a clear chain of custody – is essential to make the case for apprehension, to allow effective judicial proceedings, and often lays the groundwork for robust truth and reconciliation processes.
The problem has never been the lack of documentary evidence, or proof of authenticity. There has been plenty of evidence, since people who brazenly and openly kill hundreds and thousands of their fellows don't bother to destroy evidence. The problem is frequently that there is so much evidence that it takes time to go through it all. It's an issue of manpower, not lack of technology.
3. During acute crises, vulnerable populations are often cut off from critical information and have limited, if any, ability to communicate inside or outside of their communities. While there are a number of existing efforts aimed at improving information flow in these contexts, many focus on the outflow of information from communities or rely too heavily on existing communications infrastructure or basic literacy.
Cell phones are cheap, easy, and do not require the development of untested new technologies. They also have the benefit of accomplishing all of these goals without much training.
4. There is often a lack of credible data and relevant information from large parts of the globe, thereby making it more difficult for the international community to identify, acknowledge and act to prevent or stop potential or ongoing atrocities.
This is not a problem technology can solve. The lack of "credible data" and "reliable information" is a problem in Western nations, despite our massive technological and educational bases. How do you expect technology to solve this problem in the 3rd world if it can't even solve it in the 1st world?