BERLIN – A U.N. report detailing the scientific evidence behind the Aug. 21 chemical weapons attack in Syria carefully avoided laying blame for the incident. But the report’s details, particularly its calculations of the trajectories of the rockets that delivered poison gas to two Damascus suburbs, point directly at President Bashar Assad’s regime, experts concluded Tuesday after a day spent studying the U.N. findings.

Until this week, the public case against the Syrian government was based on trust in American, British and French assessments that were based largely on logic and conjecture but provided little detail about where information had come from. But the U.N. report, released Monday in New York, was filled with details gathered by inspectors from the Organization for the Prohibition of Chemical Weapons and was written with care so as to provide evidence without taking sides.

Specialists, however, said the report provided undeniable evidence that the rockets were launched from points outside the control of Syrian rebel fighters.

“If the U.N. inspectors correctly calculated the trajectories, it certainly seems to indicate that the chemically armed rockets were fired from government-controlled land,” said Peter Bouckaert, Human Rights Watch emergencies director and weapons expert. “It’s clear and convincing evidence.”

The key to that conclusion lies in the investigators’ determinations of the azimuths for the rockets they inspected. An azimuth is a way of indicating direction on a circle from any point. Lines drawn along those azimuths, taking into consideration the known maximum range of the rockets that hit Moadamiya and the estimated range of the rocket that hit Zamalka, intersect at the base of the 104th Brigade of Syria’s Republican Guard, on a hill overlooking central Damascus.

The base is adjacent to the Syrian Scientific Studies and Research Center, which is suspected of being the root of Syria’s chemical weapons program; the base itself is said to be home to Syria’s chemical warriors. Bouckaert added that the early rockets can’t definitively be shown to have come from the Republican Guard base. But their flight paths offer little, if any, ground on which rebels can operate, leaving little doubt as to who fired them. The trajectory includes the Republican Guard base, the presidential palace and grounds, at least one other military base and the edges of the government-controlled airport.