Updated

Authorities were in their fifth day Monday of investigating the case of a pizza deliveryman who was killed when explosives strapped to his neck detonated after he robbed a bank. An FBI agent said over 100 leads had been received.

FBI Special Agent Bob Rudge told Fox News Monday that leads were coming in every hour and were being followed up by some 50 investigators.

Evidence, including pieces of the bomb and the bank-robbery note, were flown to an FBI (search) lab in Quantico, Va., for further inspection, according to Ken McCabe (search), an FBI agent investigating the case.

McCabe told Fox News Monday that FBI handwriting experts were still comparing the note delivery man Brian Douglas Wells (search) showed bank tellers during the robbery and samples of his handwriting to determine if there was a match.

Investigators were also looking into the death of Wells' co-worker Robert Pinetti, 43, who called paramedics Sunday morning and said he wasn’t feeling well, but then refused treatment.

Pinetti was later found dead in his parents’ home, where he lived.

“We really don’t have any information that would conclusively link the two deaths together,” Rudge told Fox News Monday, adding that police were not discounting any possibilities.

The community had been very helpful, Rudge added, but the case remained a mystery.

"We really don’t have any idea how close we are to conclusion, but I can tell you we are working on this 24-7," he said. "I’m confident we will bring this matter to conclusion."

Wells, 46, answered a delivery call Thursday to a mysterious address in a remote area and ended up about an hour later at a bank wearing a bomb.

As the time bomb ticked, Wells tried in vain to convince police, who were waiting for the bomb squad to arrive, that he was forced into the crime.  He died when the explosives detonated.

WJET-TV of Erie (search), Pa., captured audio and video from Wells as he sat handcuffed in front of a state police cruiser.

"Why is nobody trying to come get this thing off me?" he asked.

Warning: Graphic Video

McCabe said the most unusual feature of the bank robbery was that the bomb was wrapped around Wells' neck.

“This is probably one of the most dangerous bombs to try to defuse," McCabe explained. "The bomb squad would have to do a hand entry and use their hands and tools and try to get it off.”

The incident “looks like a good old-fashioned bank robbery with a new twist on it,” said McCabe, adding that police were classifying Wells' death as homicide, with no evidence it was suicide.

No one else was hurt in Thursday's explosion, which happened in front of law-enforcement officers as they waited for a bomb squad (search) to arrive.

A state police spokesman confirmed Friday night that Wells had made a number of statements, including that he had been forced to rob the bank.

The tape shows Wells telling authorities someone had started a timer on his bomb under his T-shirt, and that there was little time left.

"It's going to go off," Wells said. "I'm not lying."

Erie Chief Deputy Coroner Korac Timon said Saturday the bomb appeared to have hung from Wells' neck, and that he had been told it was of a "very sophisticated construction."

Rudge called the case unusual, noting that while bank robbers sometimes claim to have a bomb, few actually do.

Linda Payne, who owns the property where Wells lived, described him as a private, trustworthy person who liked music and cared for three cats. He was a friend of Payne's husband, who also had been a pizza deliveryman, she said.

"I couldn't believe that he would rob a bank. He doesn't care that much about money," Payne said. "I think somebody lured him into that place delivering a pizza, dropped a bomb on him and sent him into the bank ... He would not have decided to do that on his own."

Wells' boss and one of the owners of Mama Mia's Pizza-Ria outside Erie, who asked that his name not be published, said Saturday he took a call Thursday for a pizza delivery but didn't recognize the address given.

He put Wells on the phone to get directions. Wells left to make the delivery and never returned, the pizzeria owner said.

The address of the delivery was a rural spot along a main drag that runs south of the city, where a gravel road leads to a television transmission tower.

According to police, Wells entered the PNC Bank branch outside Erie on Thursday afternoon and produced an "extensive note" demanding money and said he had a bomb.

Wells left with an undisclosed amount of money and got into his car. Police surrounded him a short time later in a nearby parking lot, pulled him out of his car and handcuffed him, authorities said.

The bomb exploded about 40 minutes after he entered the bank.

Authorities obtained a search warrant and took evidence from Wells' home, but a state police spokesman refused to say what was taken. The evidence arrived at FBI laboratories in Washington, D.C., but Rudge could not say how long testing would take.

State police forensics teams also searched near the spot of Wells' last pizza delivery. It was not known what, if anything, they found.

The Associated Press and Fox News' Amy C. Sims contributed to this report.