tangaroa | Signs point to Syrian responsibility in al-Ghutah gas attack (Reply)

Ake Sellstrom, the chief UN investigator on site in Ghutah, released a report that confirmed the use of sarin in Ghutah without saying who was responsible. Though the report does not say as much, I've seen bloggers state that this report traces the sarin rocket trajectory back to Syrian forces.

The report does trace the trajectory of the rockets at two impact sites. Two rockets were fired into Moadamiyah with an azimuth of 214-215 degrees. One of them was identified as a M14 artillery rocket, and the location of the other impact site is "fully congruent" with being from the same launcher. A 330mm artillery rocket fired into Ein Tarma stuck into the mud at an azimuth of 105 degrees. Samples were taken from the areas of these impacts.

Looking at the tables of chemical sample tests, the samples taken from the rocket at Moadamiyah on August 26th all show negative for any CW agent, although in the column for "degradation or and by-Products" both laboratories found diisopropyl methylphosphonate (DIMP), a sarin byproduct, in one of the 13 samples. One of the two laboratories found byproducts in several other Moadamiyah samples while these samples came out clean from the other laboratory. Both labs detected sarin and/or its byproducts in most of the samples that were taken from the Ein Tarma rocket on the 28th and the 29th. Meanwhile, two different laboratories found strong evidence of sarin exposure in blood and urine samples taken from residents at both sites.

It seems to me that the Moadamiyah rocket might have been conventional, with the sarin byproducts coming by air from another source. The evidence is stronger for the Ein Tarma rocket being a chemical weapon.

The report also describes the rocket type that Brown Moses calls "UMLACA", which appears to be the chemical weapon carrier. Sellstrom is not clear whether or not the 330mm rocket in the mud at Ein Tarma is one of this type, and he provides no more detail on the trajectory of these rockets other than their having "arrived from the northwest".

The Rogue Adventurer has what appears to be a photo of the Ein Tarma rocket. The size and tail appearance match the UMLACA. He says that the same type of weapon has also been seen using a conventional warhead in past attacks.

Signs are now pointing toward the Syrian government being responsible for the attack.

Various blogs are saying that the trajectories point back to Syrian government installations. I personally can't say, but I'll accept that for now.
The UMLACA weapons broke on impact in a way that suggests they carried a non-explosive weapon, making them the most likely carriers of the sarin gas.
The weapons worked, which suggests construction by the state following a chain of testing and development rather than being built in some guy's workshop from scrap parts.
These appear to be custom weapons made for an Iranian launch platform that the Syrian government is likely to have more of than the Muslim Brotherhood.
The sarin attack may have coincided with a conventional attack upon the same locations, suggesting the same party was responsible.

As for the theories of Muslim Brotherhood responsibility:

Syria and Iran have claimed that some of the videos released the day of the attack were produced earlier, but that only discredits some of the videos and none of the other evidence. It is quite possible that the Muslim Brotherhood had gassed the Latakia children with captured or homemade sarin and kept the videos in reserve to be used in a future disinformation campaign. That is the sort of thing the Brotherhood would happily do, and they would have released the videos for improved PR and sympathy when they got news of an actual chemical attack. Again, if that had actually happened, it discredits only those particular videos and nothing else. Syria has yet to produce evidence of its claim of the children in the videos being the ones missing from Latakia.
The strong identification of the sarin's artillery delivery system has discredited Yahya Ababneh's theory of underground bunkers of Saudi-supplied sarin being the cause, as has the lack of any such bunkers being discovered by Syrian forces.
Yossef Bodansky has yet to produce his video of MB forces in al-Ghutah switching loyalty to the Syrian government on Syrian television or to show that these same people are the victims of the chemical attack. He has followed up his prior posts with a whole bunch of details that nobody else is reporting with no evidence and insufficient sourcing to verify them, which is his usual style. His claim that the sarin was not military grade, if true, can be explained away by Syria doing things cheaply after two years of war and/or not having as advanced a chemical weapons program as Russia.
Pierre De Prata's allegation of overhearing MB forces taking responsibility for the attack is hearsay, possibly misheard, and unsupported by any further information, and his witness Domenico Quirico refused to back him up.
The hacked Col. MacDonald emails prove nothing more than a guy consoling his upset wife.

Questions still remain:

We don't know for certain whether the UMLACA is only a Syrian weapon or one held by both sides.
We don't know for certain where the launch points were and whether they were controlled by Syrian forces at the time.

Perhaps the strongest sign of Syrian responsibility for the attack is that they have yet to come out with a good explanation of how the Muslim Brotherhood could have carried out the attack that fits the evidence we now have. I can imagine several possibilities, but none of them have been proposed yet. If Syria had evidence of events taking place along one of those lines, they would have mentioned it as a possibility. They haven't, therefore it's unlikely.