Mr. Dalli, who in December filed a harassment complaint with the police against Ms. Caruana Galizia, said he “was very angry” when he heard she had been killed. “It basically removed my chances of exculpating myself from everything she said about me,” he said.

Justin Borg-Barthet, a Maltese legal expert who lectures at the University of Aberdeen in Scotland, said the legal system, built up during British colonial rule, has been so steadily eroded by political meddling and constant reshuffling of the police leadership that virtually nobody expects justice to be done in the case of the murdered journalist.

“Trust does not function as a reliable constitutional principle when people are untrustworthy,” he said.

Ms. Caruana Galizia, 53, had an insider’s grasp of that world. “There are crooks everywhere you look now. The situation is desperate,” she wrote in her last blog post Monday afternoon, just a half-hour before she left her family home by car to run errands and was blown to pieces.

The bombing stunned Malta, where known criminals sometimes attack one another but where the streets are safe and violence against public figures is extremely rare. It also sent tremors through the European Union, which took in Malta as a member in 2004 and, at a time of deep disillusionment with the “European project” in Britain and elsewhere, has often pointed to Malta’s economic success as an example of how Europe can work.

“Such incidents bring to mind Putin’s Russia, not the European Union,” Sven Giegold, a prominent German member of the European Parliament, said of the killing. Chancellor Angela Merkel of Germany, speaking to fellow European leaders at a summit meeting in Brussels on Thursday, expressed dismay and outrage at the killing.