WHEN he took office as Colombia's justice minister more than four months ago, 29-year-old Fernando Carrillo, a black belt in karate with a master's degree in public law and finance, sat down in what many people agree is the hottest seat in the country.Mr. Carrillo, a member of the Liberal Party, is the youngest cabinet member in Colombian history with the exception of Luis Carlos Galan, who at age 27 served as education minister. Mr. Galan was gunned down by drug traffickers during his 1989 presidential campaign at age 46. Now Carrillo is responsible for overseeing the trial of Galan's alleged killer, called one of the most dangerous criminals in the world. Pablo Escobar, the reputed leader of the Medellin cocaine cartel, surrendered last June under a government leniency program prohibiting his extradition. His trial is scheduled to begin in mid-1992. Past drug trials have proved difficult in Colombia, where more than 242 judges and other judicial employees have been assassinated since 1981. Keeping judges and witnesses out of the violent reach of traffickers is just a small portion of the work that Carrillo faces in the Augean stables known as the Colombian Ministry of Justice. The ministry is cluttered with tens of thousands of criminal cases, unresolved because of a crushing bureaucracy, lack of evidence, and little or no protection for those in charge. The biggest problem is a shortage of money to unclog the system and make it work, judicial officials say. "I realize that justice reforms mean little without the money to back them up," says Carrillo, sitting in his office overlooking a busy Bogota avenue. "This is my toughest fight." The minister admits that he is up against the wall. Justice expenditures, equivalent to only 1 percent of the national budget, have shrunk in real terms this year compared with last. Colombia's 1991 outlay for the justice system is virtually the same as the 1990 level of $56 million. The drop has come despite officials' panegyrics about a rebuilt branch and structural reforms by the dozen. Among the most publicized innovations is last year's creation of a special jurisdiction of 82 "faceless judges." The government is trying to keep the judges' identities secret in order to protect them from drug traffickers, terrorists, and other dangerous criminals. But the chronic lack of money is preventing the Ministry of Justice from hermetically sealing off the judges from the dangerous environment outside their offices, judicial officials say. Many judges, with neither bodyguards nor armored cars, are forced to take public transportation to and from work. Most of them earn less than $1,000 a month. "The faceless-judge jurisdiction is absurd because everybody including myself knows who they are," says Antonio Suarez, the head of the national judges union known as Asonal. "Carrillo is a young man full of good intentions, but he is running up against the state's lack of will to provide the justice system with the resources it needs." Mr. Suarez mentions recent assassinations of a judge and a court investigator in the southern city of Cali as proof that judicial workers are more endangered than ever. Neither of the victims worked in the special jurisdiction, but their murders by unidentified gunmen underscored the vulnerability of the branch as a whole. Carrillo says improving security for judges is just one of many steps that must be taken to ensure justice. The minister labels as essential several reforms dictated by Colombia's new constitution, including the creation of an attorney general's office to bring cases against criminals and to oversee the gathering of evidence by police. Before, the judges themselves were in charge of developing the cases in a system that increased their exposure to threats and violence. Now they will simply hear evidence and hand down rulings. "The major source of impunity in Colombia is the lack of coordination in investigations," Carrillo says in his quiet, lilting voice. "The attorney general's office should solve this problem." The United States has guaranteed $36 million over the next three years to help establish the system. The justice minister says much of his work involves securing US cooperation in other areas as well. Colombia plans to use evidence provided by US authorities to try Mr. Escobar and other drug suspects in trials beginning next year. Though the justice minister acknowledges that the US has already provided important information, he says that much more remains to be delivered. "We're going ... to give these criminals the sentences they deserve according to the evidence, much of which is coming from the outside," Carrillo stresses. "We want to see them behind bars for 15, 20, even 30 years. I feel a personal responsibility to make sure this happens." "Personal responsibility" is a phrase that crops up frequently in an interview with the justice minister. The words should not be taken lightly, since many of the structural reforms now being wrought in the judicial system are the fruits of Carrillo's labor. Not only did Carrillo preside over the justice committee of this year's constitutional assembly, but he also headed the movement that led to the assembly's convocation in the first place. For decades, politicians have proposed the reform of Colombia's 19th-century constitution, but each new effort failed for one reason or another. In 1986, while studying for his law and finance degree at Harvard University in Cambridge, Mass., Carrillo became obsessed with modernizing Colombia's constitution. In January 1990, Carrillo and another young Harvard graduate, Jose Manuel Cepeda, met in a Bogota restaurant, where they decided to take the reform project to the Colombian people. That conversation led to an unofficial plebiscite in the March congressional elections, in which 90 percent of voters approved the idea of constitutional reform. The work by 90 elected delegates, including Carrillo, began in February 1991 and ended in July. The result, most analysts agree, is a constitution that promises wider democracy and a stronger judiciary. As head of the assembly's justice committee, Carrillo frequently spoke of the need to transform the paper into reality. He got his chance in early August, when President Cesar Gaviria Trujillo named the young constitutional expert to replace the resigning Jaime Giraldo at the justice ministry. Mr. Giraldo's resignation came amid a scandal over special privileges, including unlimited visitors, granted to Escobar in his Medellin jail. Carrillo says he has already cut such privileges. "Escobar is finding that with each day he becomes more and more of a common prisoner," he says. The young man says his goal is to leave the judicial branch capable not only of processing a suspect like Escobar, but of satisfying Colombians' yearning for an end to the plague of impunity.