http://www.bbc.co.uk/news/world-europe-33525145
The memorial project is based on the work of Father Patrick Desbois, a French Catholic priest, whose Yahad-In Unum organisation is documenting all killing sites across eastern Europe and interviewing witnesses still living in the villages.
In his book, Holocaust By Bullets, he describes how many regular people were forced, sometimes under threat of death, into assisting: feeding the Germans, collecting valuables, digging and then filling in the pits, many of which still contained living people.
"The ground moved for days afterward," he was told repeatedly.
These shootings were a more intimate form of extermination than the killing factories of Auschwitz and Treblinka. Virtually everyone in the communities was touched in some way.
"One day we woke up and we were all wearing Jewish clothes," he quotes one villager as saying.
The Holocaust by Bullets: A Priest's Journey to Uncover the Truth Behind the Murder of 1.5 Million Jews