The account is that a nineteen-year-old named Ali Marjek raped and killed three young boys in Damascus, and was hanged there on March 27, 1977. The announcement of his execution described the case as the only one of its kind in Syria's history.
That is the whole of it. The source is a single paragraph in Michael Newton's encyclopaedia of modern serial killers, which itself opens by saying that few details are available. Searches in English have found nothing beyond copies of that paragraph, including on this archive's own page.
No victim is named. No method is recorded anywhere accessible, and none is asserted here. No date is given for any of the killings, no trial is documented, and no Syrian record has been located.
Two figures in the fields above are inferences rather than findings, and are marked here as such. The birth year of 1958 is worked back from his age at execution. The span of 1976 to 1977 does not appear in the source at all; only the execution is dated.
The entry is kept as a record of an execution and of an allegation, not as an account of three murders. It belongs with Schultz, Furuya Sokichi, Peter Kulaxides, Major Singh, Roman Burtsev and Samuel Green in this archive: entries whose entire source base is one paragraph, retained because the absence is itself worth recording.