THE QUANTITATIVE ANALYSIS CONSIDERED THE NUMBER OF ARTICLES ON THE SUBJECT IN EACH NEWSPAPER, THE SIZE OF THE HEADLINES, THE SURFACE AREA OF EACH ARTICLE, AND THE NUMBER OF PHOTOGRAPHS DURING THE 96 DAYS OF STUDY. THE QUALITATIVE ANALYSIS EVALUATED CONTENT AND STYLISTIC FEATURES AND THEIR UNDERLYING LOGIC. THE ANALYSES INDICATED THAT, DURING AN INITIAL PHASE OF COVERAGE, THE THREE PAPERS SUCCEEDED IN CREATING A 'TERRORISM MYTH' BY LINKING THE MURDER TO GERMAN TERRORIST ACTIVITIES. THE MYTH WAS ALL THE MORE EFFECTIVE SINCE IT DREW ON BOTH REAL AND IMAGINARY ELEMENTS: THE ACTUAL MURDER OF A SWISS POLICE OFFICER LINKED WITH AN UNSUBSTANTIATED TERRORISM THEORY. BOTH ELEMENTS ARE USED TO VILIFY THE OFFENDERS AND TO TAP DEEP-ROOTED FEARS AND SUSPICIONS IN THE SWISS POPULATION. WHEN THE POLICE INVESTIGATION REVEALS THAT THE VICTIM WAS MURDERED BY A FELLOW POLICE OFFICER, THE NEWSPAPERS FAIL TO ACCEPT THE CORRECTNESS OF EXPERT RESULTS. WHEN THE MURDERER CONFESSES THE PAPERS ACKNOWLEDGE THE FACT, BUT CAST DOUBT ON THE INTENT AND CRIMINAL RESPONSIBILITY OF THE OFFENDER. DESPITE THE EVENTUAL INVALIDATION OF THE TERRORISM THEORY, THE THREE INDEPENDENT PAPERS (NEITHER OF WHICH ESPOUSES EXTREMIST IDEOLOGIES) SUCCEEDED IN CREATING A PROFOUND SENSE OF INSECURITY IN THE POPULATION, A FEAR OF TERRORIST ACTIVITIES, AND A SUSPICION TOWARDS CERTAIN YOUNG PEOPLE. TABLES AND 35 REFERENCES ARE INCLUDED. --IN FRENCH.