a single shred of evidence to back your stupid claims that Israel wasn't guilty for the massacre

Strange that not one single decent government blames them for it then.

They accept indirect responsibility as the authority at the time.
They accept that the commander should have anticipated something, and acted sooner, but they are not guilty of any massacre.

All the massacres in those camps, including this the only one you care about, were committed by other Arabs as is the the appalling suffering now of the Palestinian refugees in Syrian camps.