Fishermen had complained for a year about the pirates who crept onto their boats at night and stole shrimp at gunpoint. Police opened an investigation and had a list of suspects but not enough proof to make arrests.
Then Israel Job Pineda made a fatal mistake. When ski-masked men brandishing pistols boarded the Santa Julia last month, he exclaimed, "Oh, it's you."A pirate shot him to death and critically wounded another man who also recognized an intruder.
Pineda's death provoked a public outcry that turned the pirates into El Salvador's top law enforcement priority.
Twelve days after the killing, hundreds of police officers converged on the fishing village of La Herradura, 27 miles southeast of the capital, to arrest the nine fishermen and merchants that witnesses had linked to the attack.
Two Salvadoran navy speedboats were dispatched to arrest fishermen aboard their boats. In all, eight people were taken into custody, but the man suspected of killing Pineda escaped.
But law enforcement officials do not expect the arrests to make a dent in the problem. Piracy remains a serious threat to an industry that provides 54,000 jobs and $65 million a year in foreign exchange, El Salvador's third-largest export after coffee and sugar.
The piracy problem plagues most of Central America. Small, poor nations do not have the resources to protect their coasts, and they are no match for drug traffickers, environmental abusers or modern-day pirates. Pirates prey mainly on shrimp boats, which are often at sea a week or more.
"There were 14 robberies last year," said Mauricio Aviles, the manager of the Salvadoran Fishing and Aquaculture Chamber, an industry association. "The navy cannot make arrests unless they catch thieves red-handed. The police are supposed to enforce the law, but at sea, there are no police."
Deputy Police Commissioner Ciro Barrera confirmed that the police have no boats.
"We cannot patrol the ocean because we do not have the equipment," he said. "We were able to make these arrests only because the navy provided the boats."
When the Santa Julia was attacked Jan. 16, no government boats or helicopters were available.
Fishing boats brought the critically wounded fisherman to shore six hours after he was shot. The man - a key witness who could identify the pirates - is in a coma.
In addition to the lack of police presence, investigators also face the difficulty of identifying stolen merchandise.
"Shrimp do not have serial numbers," Aviles noted. In fact, the three merchants arrested on charges of receiving shrimp from the Santa Julia were later released for lack of evidence.
Prosecutor Mario Machado said he worries what will happen to the rest of his case because witnesses are being intimidated by suspects' relatives. One witness has already disappeared, and two others have received death threats, he said.
Those witnesses have been relocated with funds provided by the owner of the Santa Julia, wealthy businessman Archie Baldocchi.
"I have no budget to protect witnesses," Machado said.
And the piracy problem is getting worse, Aviles said.
"Before, the robbers just took merchandise," he said. "But now, people are dying."