The former sailor arrested for sending envelopes containing castor seeds to the White House and Pentagon was reduced in rank twice before he left the Navy in 2002.

William Clyde Allen III, 39, of Logan, Utah, was in custody on Wednesday and is seen grinning in his mugshot. He served in the Navy from 1998 to 2002 as a fireman apprentice on supply and support ships.

Seven months before he was discharged, his rank changed from E4 to E2, according to his service record which DailyMail.com obtained on Thursday.

He was a student in Illinois until 1999 then went to work on board USS Supply until it was decommissioned in 2001.

He then went to work USS Detroit until 2002. In March that year, his rank changed was reduced E4 to E2 though it is not clear why. He left the armed services in October 2002.

During his time in the Navy, he was awarded the 'E' ribbon twice, a National Defense Service Medal and two Sea Service Deployment Ribbons, all of which are standard issue.

Details of his departure from the armed services and what he has been doing since were not immediately available on Thursday morning.

In 2008, Allen was arrested for aggravated assault in Logan and was sentenced to one year in jail as part of a plea deal.

Fox News reported that officials were led to Allen's home after his return address was on one of the envelope mailed to the Pentagon.

He was arrested in Utah on Wednesday and was taken into custody. Police have until Friday to file charges.

William Clyde Allen, 39, of Logan, Utah, has been arrested. He is seen above grinning in his mugshot

Law enforcement officers search William Clyde Allen's house in Logan, Utah, wearing protective clothing

A law enforcement officer dons a mask to search the property in Utah

Allen served in the Navy from 1998 to 2002 as a fireman apprentice on supply and support ships. He is shown right in a 2008 mugshot after being arrested for aggravated assault in Logan, Utah. He pleaded guilty and spent one year in prison

Pentagon spokeswoman Dana White made the clarification on Wednesday and said the FBI was still investigating.

Ricin can be extracted from the seeds which can be lethal if eaten in large quantities but otherwise harmless.

If a person is exposed to ricin in its extracted form, they can die within 72 hours by inhaling much smaller amounts of the toxin which causes respiratory failure.

None of the envelopes reached their intended targets.

They set off alarms in off-site mailing facilities which detect ricin or other poisonous elements in incoming packages.

The first two envelopes that were addressed to Secretary of Defense James Mattis and Chief of Naval Operations John Richardson.

They triggered alarms during screening at a mail facility which is not inside the main building but is nearby, defense officials said. They were sent to the FBI for additional testing.

Fox News reported that officials were led to Allen's home after his return address was on one of the envelope mailed to the Pentagon

Allen was taken into custody at the scene. Investigators are seen outside the home

All mail that was sent to the Pentagon was placed under quarantine as a precaution. FBI and law enforcement officers put on masks and hazmat suits to enter the home

At around the same time, two people were hospitalized after being exposed to a white powder that was contained in mail sent to Sen. Ted Cruz's Houston campaign office.

Their injuries are not known. Neither of the victims worked for Cruz's campaign.

It is not known if the two incidents are linked or what the substance sent to Cruz's office was.

After the incident at Cruz's office, the Houston Fire Department conducted tests in the building but no harmful substances were found.

All mail sent to the Pentagon via the US Postal Service on Monday was placed under quarantine as a precaution and all workers from Cruz's Houston campaign office were evacuated.

All mail that was sent to the Pentagon was placed under quarantine as a precaution.

US Defense Department personnel work in the mail room at the Pentagon where two of the envelopes were found yesterday. The envelopes contained castor seeds and not actual ricin but they triggered alarms in the screening process

A third envelope was reported by the Secret Service as being intercepted before arriving at the White House

Officials say the first two were addressed to Secretary of Defense James Mattis (pictured left) and Chief of Naval Operations, John Richardson (right)

Ricin exposure can lead to death if the toxin is inhaled directly. It is commonly used in terror plots.

It remains unclear what form it was sent to the Pentagon in. In a statement, the FBI confirmed its investigation.

'On Tuesday, October, 2, 2018, in coordination with the Pentagon Force Protection Agency, FBI Special Agents took possession of two suspicious envelopes that had been screened at the Pentagon mail facility.

'Those envelopes are currently undergoing further testing.

'As this is ongoing, we will have no further comment,' a spokesman said.

Ricin causes a painful deaths which begin with nausea and vomiting.

The toxic components then cause internal bleeding and ultimately lead to respiratory failure.

The envelopes were intercepted in the mailing facility which is not inside the Pentagon (pictured on Tuesday)

Several terror plots which use the toxin have been foiled in Europe in the past including an intended attack on a London Underground station in 2003 and a separate attack in Germany in June this year.

The envelopes contained castor seeds which (file image shown) which ricin can be extracted from. They can cause deadly illness if eaten in large quantities but do not pose any form of risk to air

After initial exposure to ricin, symptoms ordinarily appear in around 10 hours and death can occur within 72 hours.

Since the anthrax attacks which killed five people after the powder was distributed through mail in 2003, the US Government has increased measures to protect workers and officials from exposure to any harmful substances.

They include putting mail through X-Ray machines and scanners which detect vapors and identify anything poisonous or toxic.

In Washington DC, the US Postal Service also samples the air as mail is being sorted before it is sent to government buildings.