As the FBI is under heavy pressure to release its evidence against 62-year-old Army scientist Bruce Ivins, skeptics say that the government researcher was singled out because he was the "weakest link." Most of Ivins colleagues say that his behavior only became abnormal after being pursued relentlessly by FBI.

The only evidence that FBI has acknowledged so far is the fact that the same anthrax that was mailed to the targets of the attack has been found in Irvins's laboratory. However, apparently at least a dozen people had access to the strain. Bruce Ivins's colleagues allege that, armed with this evidence, the FBI began to pressure the people at the laboratory and singled out Ivins because he was most susceptible to being intimidated.

Dr. W. Russell Byrne said that FBI harassed Ivins’s daughter repeatedly to acknowledge that her father was involved in the attacks, showing her gruesome photographs of victims of the anthrax letters and telling her that Ivins was responsible. They also tried to "bribe" his adopted son by suggesting that he might be able to collect the $2.5 million reward for solving the case and buy a sports car.

Another Ivins colleague, Dr. Kenneth W. Hedlund, backed Byrne's allegations and said that the FBI scapegoated Ivins because they thought he was the weakest one in the team and they needed to find somebody to blame for the unsolved attacks. Yet another scientist, David R. Franz, said that it is highly unlikely, very improbable, that Bruce Ivins could have manufactured the anthrax powder at the government facility without being noticed.

Most of Ivins' co-workers testified that they did not notice anything amiss in Bruce Ivins' behavior before his mental health began deteriorating following the recent investigation. He would apparently weep at his desk, and was unable to do his work.

Ivins died Tuesday at Frederick Memorial Hospital after taking a massive dose of prescription Tylenol mixed with codeine. Even if was indeed guilty of the 2001 attacks, there is still the issue of how safe are exactly the United States' many bio-defense laboratories, as it appears that no actual psychological screening of the personnel and no failsafe security protocols are in place.