French mood sours as violent crime soars. The law-and-order issue is having serious repercussions for Mitterrand

Violent crime has been one of the dominating issues in recent weeks here, depressing this nation's mood and having negative repercussions for the presidency of Francois Miterand.

Verbal violence has followed the physical assaults. respected national newspapers have begun to look like scare tabloids, with such screaming, front-page headlines as ''France is scared'' and ''who is torturing our grandmothers? shouting matches have erupted in the National Assembly.

The opposition has taked the offensive. It accuses the Socialist government of incompentence and laxity in managing the police, capping its charges with an attact on the government's 1981 decision to ban the guillotine.

In a recent incident of mindless violence, two men died when an inemployed youth fired seven times into a cafe croweded with Turkish immigrants. Other incidents have included the murder of a peacefully striking Turkish worker by his employer and the robbery and murder of nine elderly women in Paris's artsy Montmartre district.

While the government denounces the opposition for ezploiting the murders for political reasons, it acknowledges that the crime issue has hurt President Mitterand. Halfway through his seven-year term, his approval rating has plummeted to an all-time low of 26 percent in the polls.

Mitterand himself admitted that public order was becoming as big a problem as the faltering economy.

To a certain extent, the alarm bells seem overdramatized. Compared to many nations, including the United States, France remains a safe country. Government figures show there are more crimes per capita in Denmark, West Germany, and Britain than in france. In a population of some 50 million, there were only 2, 701 homicides here of all kinds in 1983

There is no evidence that murder has become a worse problem since capital punishment was abolished.

Moreover, French police hold far greater powers than do their counterparts across the atlantic. Every Frenchman carries an identity card, which he must show to police on demand. no warrants are needed -- and little explanation must be given before jailing a suspect.

When the Socialists won power in 1981 they tried to increase civil liberties. They abolished the death penalty. Justice Minister robert Badinter granted amnesty to 6,000 petty criminals and dismantled the state security courts. These actions were not popular.

Crime has increased as France urbanized during the last 20 years. Polls show that after unemployment, lack of security is the French people's greatest worry.

As a result, the Socialists soon reversed course. Plans to repeal a law extending police powers were dropped. now Interior Minister Perre Joxe says striter firearm laws and more police with more powers are needed.

What seems most explosive in the storm over law and order is the immigrant element. As unemployment and crime have mounted, so have feelings against the large guest-worker population, much of it from Arab North Africa. Jean-Marie Le Pen's racist, anti-immigrant National Front Party polled more than 10 percent in June's elections for the European Parliament.

Had his racist harangues incited killers? To underscore that possibility, French national newspapers reprinted an interview with a Turkish journalist in which Le Pen declared: "Migrant workers are now the biggest disaster for a country with low birth rate. We are ready to take up arms to prevent the destruction of France." Le Pen complained he was quoted out of context.

Nevertheless, the incident underscores the volatility of France's mood. Perhaps the murders and the interview publicity will weaken Le Pen's brand of extremism. More likely, though, Frenchmen will continue to blame much of their economic and security difficulties on the foreigners.

At least that is what Paris mayor Jacques Chirac, leader of the Gaullist opposition and Mitterrand's likely opponent in the 1988 elections, seems to feel. His criticisms of the government's security policy have included harsh words against immigrants.

The law-and-order issue seems to pack a strong punch: Polls suggest Chirac would defeat Mitterrand if elections were held now.