Two years after an Erie pizza delivery man robbed a bank and then was killed when a bomb clamped to his neck exploded, the FBI has made no arrests in the bizarre and complex case but has developed "promising" leads following more than 1,000 interviews, the agent overseeing the investigation said.

"We're certainly in a better position than we were two years ago. We've made a lot of progress. We've identified a couple of avenues of investigation that are promising to investigators," Robert Rudge, assistant special agent in charge of the Pittsburgh FBI office, said Friday.

"It means we have some theories, maybe some groups of individuals we may be looking at attached to those theories. I can't tell you who those groups of people might be," Rudge said.

Brian Wells, 46, died two years ago today after robbing a bank just outside Erie. A mild-mannered delivery man, Wells was preparing to watch movies with his mother and sister after his shift at Mama Mia's Pizza-Ria when he took a last, fateful order to an address near a television tower.

A short time after leaving with the two pizzas, Wells appeared at the bank -- with a bomb locked onto his neck and a T-shirt with the word "Guess."

Investigators believe Wells was outfitted with the bomb by an undisclosed number of people who had targeted him and then given a complex set of instructions to follow after robbing the bank.

The bomb detonated a short time later after state police stopped Wells and handcuffed him. Investigators discovered nine pages of handwritten notes sprinkled with maps and drawings that gave minute instructions for Wells to follow. They also found a cane-like shotgun. Rudge said investigators believe the bomb, the gun and the notes were all crafted by the same person.

Citing FBI policy, Rudge would not comment on any possible suspects. He also would not specifically address a story this month in the Erie Times-News that agents were focusing on a convict in Washington state who was in Erie at the time of Wells' death and living with a friend near the site of the pizza delivery.

The man with whom the newspaper said the convict was living had a shady past himself. William Rothstein, who died last year, told police that he had stored the body of his former fiancee's boyfriend in his freezer after she shot him.

Even as a multi-jurisdictional task force continues to work the case on a daily basis, Wells' younger brother, John, 42, of Glendale, Ariz., has become increasingly angry and frustrated with the FBI and its handling of the case.

Wells said he has limited contact with the FBI, sometimes has to leave several messages before someone calls him back, and that information presented to him last week by the new agent in charge of the Erie field office left him with the impression that no significant progress had been made in the past year.

"I think the investigation has been flawed from the beginning," Wells said from Erie, where some of his family still lives. "It's the same thing -- we're investigating, we're getting tips and we're tracking down leads. I'm like, the family needs a lot more than rhetoric. It needs results."

Wells' primary gripe is that the agency has not declared that his brother was an innocent victim. As well, he is upset that investigators have not released the full text of the notes. Four of the nine pages have been released almost in their entirety, and Wells has placed them on his Web site, www.brianwells.net.

Wells believes that the more people who see the notes, who read their domineering tone, the better the chance that someone will recognize the author. Rudge, however, said the FBI needs to hold back some details so agents can assess whether someone who comes forward with specific information is telling the truth.

"I think they spent the better part of these past two years trying to frame my brother instead of following the evidence they had," Wells said. "They're trying to find evidence that supports a story they would like to tell. They're trying to implicate my brother in something he had no part in."

Rudge, who ran the FBI's Erie field office when Wells died, was unable to say definitively whether Wells was a participant or a victim.

"That's a big sticking point with the family, which we certainly understand. I wish I could say with a definitive statement that Brian was a total victim. That's still on the table. He may well be. He may well have been confronted at gunpoint, forced to wear it and carry out that plan," Rudge said. "Unfortunately the evidence doesn't speak to whether he's a total victim or complicit in some way. There's some things I can't go into why we have that question in our mind."

Whoever set up Brian Wells to die, the real reason was far from the ostensible motive of robbing a bank and getting the $250,000 mentioned in the note, Rudge said.

An FBI profile of the so-called "mastermind" of the scheme described him as manipulative, controlling, frugal and a pack rat -- and, of course, adept at working with wood, metal and electricity. That mastermind wanted to kill whoever was wearing the bomb and anyone in the vicinity, Rudge said.

"It's not a bank robbery. It's not about money. This was basically a sadistic way of killing someone," Rudge said.

Investigators believe Wells was targeted because of his compliant nature; the assumption is that the mastermind behind the plot could anticipate how Wells might react if conftronted by a group trying affix an outlandish device to him.

Wells' killers probably put him under surveillance and might even have had other food delivered by him as part of a scheme that was months in the planning, according to Rudge.

"The last thing the mastermind would have done would have been to leave to chance who was going to show up and deliver the pizza that day," Rudge said. "The mastermind would have no idea otherwise if it would be a 6-5, 350-pound bodybuilder to deliver the pizza."

Investigators believe that Wells was the person for whom the neck bomb was destined, and that the mastermind knew Wells would be the one to deliver the order of two sausage-and-pepperoni pizzas.

John Wells is not convinced. He dismissed the FBI's behavioral analysis of the mastermind, saying that profilers are fallible, and added that he is convinced his brother was picked at random to serve as the weapon in a plot to kill state troopers.

"When they ordered that pizza, they didn't care who they got," Wells said. "If someone wanted to kill my brother, they would have shot him in the back of the head in the woods."