report on what happened on august 21st, when the u.s. says 1400 syrian civilians were killed by the syrian regime's use of chemical weapons. >> reporter: that's right. monday, everyone is telling me that's when we should see this report. it will be a very detailed document, showing basically everything from how the samples came out of the ground to what finally was in them. now, one western diplomat is saying to me that this will be able to suggest potentially who was behind it. it's not the u.n. inspector's mandate to assign blame but the level of detail they put in this report, this western diplomat says may allow some people to draw conclusions of who was behind it. there are some people speculating that perhaps syria's move today is preempting this particular report. we have to wait and see quite how that develops. but monday, we'll see this definitive report from the u.n. which they say is entirely independent and credible, specifying what was used on the 21st of august and perhaps hinting with enough detail so people can draw conclusions who