Saeed al-Qashash was born in 1979 in Amman, Jordan, into what was described as a middle-class family living in the suburbs of the capital. Little is known about his early childhood, but reports from Jordanian news archives and trial records indicate that he was a quiet and academically capable student. He attended local schools in Amman and eventually enrolled in a nearby university or training institute, where he studied alongside his classmate Atta Shalan, who would later become one of his victims.

By 1998, Saeed was 19 years old, still living with his parents and several siblings. Described by acquaintances as reserved but prone to erratic moods, he reportedly experienced tensions within the household, possibly involving disputes over family expectations and personal failures. Although specific motives remain unclear, some regional reports suggested that Saeed struggled with psychological distress, jealousy, and anger toward family members, particularly regarding perceived humiliation and conflict over social behavior or finances.

The Qashash family was well known in their neighborhood, and their home—located on the outskirts of Amman—was described as modest and multigenerational. In contrast to his family’s social reputation, Saeed was increasingly isolated, spending long periods alone and avoiding extended relatives. There is no evidence that he had prior criminal history, though prosecutors later characterized his demeanor as "cold and calculated."

On the afternoon of June 10, 1998, Saeed al-Qashash carried out one of the most shocking family massacres in Jordan’s modern history. At his family home in Amman’s suburban outskirts, he executed a carefully planned series of killings that left 12 people dead, including 11 of his own relatives and a classmate.

According to investigators, Qashash first lured 19-year-old classmate Atta Shalan to the family home’s basement under an undisclosed pretense. Once there, he shot him in the back of the head with a 7mm pistol. Over the following hours, he methodically invited each of his family members—his mother, father, two brothers, four sisters, a brother-in-law, and two young nephews (aged two and three)—into the same basement, where he killed them in the same execution-style manner.

The victims were identified as:

Amin al-Qashash (father)

Thuria (mother)

Mohammed and Mostafa (brothers)

Karimeh, Wafa, Mervit, and Insaf (sisters)

One brother-in-law (name unreported)

Two nephews, aged 2 and 3

Atta Shalan (classmate)

After murdering all twelve, Saeed stacked the bodies in a pile, covering them with blankets and carpets before sealing the basement entrance using bricks and cement to hide the crime. He then fled Amman, attempting to disappear before the murders were discovered.

Authorities became suspicious when neighbors reported a foul odor and the sudden disappearance of the Qashash family. Two days later, police discovered the sealed basement and uncovered the bodies. Saeed was arrested on June 12, 1998, reportedly showing no emotion during interrogation. He confessed fully, describing how he killed each family member one by one. His statement indicated premeditation, though no clear motive was ever established. Psychological assessments suggested he might have experienced extreme paranoia or psychosis, though he was deemed mentally competent to stand trial.

The case shocked Jordanian society, dominating newspapers and national television throughout 1998. In November 1998, Saeed al-Qashash was tried before the Amman Criminal Court on 12 counts of premeditated murder. During proceedings, he pleaded for mercy, telling presiding judge Mohammed Ajamieh, “Please spare my life,” but the plea was rejected. The court ruled that his crimes were deliberate and coldly executed, leaving no grounds for leniency.

Qashash was sentenced to death by hanging. Reports from the time noted that he remained expressionless as the sentence was read, showing no reaction or outward remorse. Appeals were denied swiftly, as the murders had provoked widespread outrage and calls for justice across Jordan.

On June 6, 1999, less than a year after the killings, Saeed al-Qashash was executed at Swaqa Prison, approximately 60 miles south of Amman.