THE SUBJECTS WERE EITHER RESIDENTS OF AN EGYPTIAN STATE MENTAL HOSPITAL OR AN EGYPTIAN PRISON. THEY WERE ADMINISTERED A BATTERY OF PSYCHOLOGICAL TESTS INCLUDING THE HAND TEST, THE WECHSLER-BELLEVUE INTELLIGENCE SCALE, AND THE THEMATIC APPERCEPTION TEST. THEIR HOSPITAL AND PRISON RECORDS WERE ALSO REVIEWED. ANALYSIS OF DATA INDICATED THAT THE MURDERERS WERE PREDOMINATELY MALE AND BETWEEN THE AGES OF 25 AND 35, WERE MARRIED, WORKED AS LAND WORKERS, AND HAD COME FROM BROKEN OR TROUBLED HOMES. THEIR USUAL MOTIVE FOR MURDER WAS VENDETTA. THERE WAS A HIGHER PERCENTAGE OF PERSONS WITH MENTAL OR SEXUAL DISORDERS AMONG THE 90 SUBJECTS THAN AMONG A GROUP OF CONTROLS WHO WERE ALSO ADMINISTERED THE TESTS. THE SUBJECTS SCORED SIGNIFICANTLY HIGHER THAN CONTROLS ON AGGRESSION-RELATED AREAS IN THE TESTS. THE EEG WAS PERFORMED ON A GROUP OF 76 OF THE MURDERERS, REPRESENTING BOTH PRISONERS AND MENTAL PATIENTS. RESULTS INDICATE THAT THE INCIDENCE OF EEG ABNORMALITY IN THE PRISON GROUP WAS 43.48 PERCENT, AND IN THE MENTAL HOSPITAL GROUP IT WAS 57 PERCENT. THE MOST IMPORTANT OBSERVATION WAS THE VERY HIGH INCIDENCE (OVER 70 PERCENT) OF ABNORMAL EEG AMONG THE PRISONERS WHOSE CRIME WAS APPARENTLY MOTIVELESS OR WITH ONLY A SLIGHT MOTIVE. REFERENCES AND TABULAR DATA ARE PROVIDED. (DAG)