It was a hot lead for detectives on a cold case. People suddenly were getting salmonella at a Minnesota restaurant more than 1,000 miles from the center of the nation's outbreak.

Not my tomatoes, protested the manager. He'd switched his supply to government-cleared fresh tomatoes and even canned ones. But a lot of his menu items had a raw jalapeno garnish sprinkled on top, and that turned out to be a critical clue in the two-month salmonella mystery.

On July 3, Minnesota e-mailed the feds. After tracing credit card receipts _ to find what the restaurant's healthy customers didn't eat _ there was good evidence that the jalapenos were sickening people. And, officials had a diagram tracing the pepper shipments all the way back to three farms in Mexico.

One of those farms shipped peppers through the same large warehouse in McAllen, Texas, where Food and Drug Administration inspectors weeks later would find a single contaminated Mexican-grown pepper being packed by a neighboring vendor.

How could Minnesota pinpoint hot peppers just days after discovering a cluster of sick residents, when federal investigators had spent weeks fruitlessly chasing tomatoes?

To be fair, "there was already some doubt about tomatoes causing this whole outbreak," cautioned Kirk Smith, foodborne disease chief at the Minnesota Department of Health.

And federal investigators say Minnesota's information came just as they were getting hints from two Texas restaurant clusters that jalapenos might play a role.

"Ours was the first that pointed specifically to jalapenos as an ingredient, not just the salsa," Smith said.

It's too soon to know if the Centers for Disease Control and Prevention improperly blamed tomatoes in early June, based on reports from the first people to fall ill in New Mexico and Texas.

"I don't think we can find fault yet," said University of Georgia food-safety expert Michael Doyle. "With tomatoes, if you looked at the initial case-control studies, they really came up high on the list."

The CDC didn't comment Wednesday.

At the FDA, food safety chief Dr. David Acheson told The Associated Press the system should be reviewed to see if it can be improved. "Did every part of this system work from one end to the other?" he asked. "I'm not saying it didn't, but I think one has to question that."

Regardless, the way Minnesota unraveled its own cases _ speedily comparing the sick and the well and then racing to track food suppliers _ offers lessons for a public health system grappling with how to handle increasingly complex outbreaks from tainted produce.

"We have got to put the appropriate perspective on this outbreak as to what went right and what went wrong so the kind of changes that are going to further foodborne disease (prevention) can be made," said Michael Osterholm, a University of Minnesota infectious disease specialist and frequent adviser to the government.

He fears the salmonella mystery may be the "swine flu of foodborne disease," and make federal health officials more reluctant to issue consumer warnings in future outbreaks unless they've found the smoking gun, an actual tainted food.

"That would be the worst legacy of this entire situation," Osterholm said.

Reports of the salmonella strain sickening hundreds elsewhere in the country began dribbling in to Minnesota's state health department on Monday June 23.

Minnesota's system is different from those of many states: Rather than county health departments initially checking outbreaks and reporting to headquarters, Smith's state office handles investigations from the beginning. By Thursday, with six cases reported, he had epidemiologists interviewing the sick: What did you eat in the few days before getting ill? Where?

By Sunday, two people had mentioned the same Twin Cities-area restaurant. Smith ordered that other patients be directly asked about that site. Monday morning, four more people fingered it _ and by lunchtime, epidemiologist Erin Hedican was on the scene.

She quickly found seven more ill: employees who ate their own meals at the restaurant and started getting sick after the first customers had. Good to know: That meant the workers weren't the source.

With the manager, Hedican combed ingredients. Any new items added lately? New suppliers? She requested invoices from shipments just before June 14, the first known meal date of one of the sick, and started the hard push to get credit card receipts so she could learn what people who didn't fall ill had eaten.

By Tuesday morning, a garnish made of diced jalapenos and red peppers was topping a list of possible suspects. Continued...