The FBI is hot on the trail of possible suspects, now being referred to as suspect one and two in the Boston marathon bombings and captured on retail store surveillance videos the day the explosions took place. The two men, clad in baseball caps and carrying backpacks were captured in the video clips as one placed a backpack down near the site of the Boston marathon bombing location.

The FBI believes the video clips are the most significant clue they've had so far in apprehending responsible parties for what happened at the Boston Marathon on Monday.

FBI Names Men in Boston Photos Suspect One and Suspect Two

As we all have become painfully aware, Monday an explosion took place near the finish line of the Boston Marathon around 2:45pm t be followed less than a minute after by a second explosion. After three days of investigation few clues had turned up regarding who what groups might be responsible for the Boston bombings until finally Wednesday afternoon hope came in the form of a Lord and Taylor retail surveillance video in which FBI agents got their first glimpse of what was thought to be a definite person of interest in the Boston marathon bombing.

Though mixed messages were sent through the media Wednesday afternoon concerning the capture and arrest of a possible person of interest, a briefing by the FBI set the record straight Wednesday evening as official informed the public that "significant" progress was being made in the Boston explosion investigation but at that point, no arrests had been made.

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The FBI appealed for the public's help Thursday in identifying two men wearing baseball caps and backpacks, one of whom was seen placing a backpack at the site of the second Boston Marathon bombing.

So what was in these videos that has the FBI convinced these men in baseball caps could be responsible for the bombings which killed three and left 176 injured? According to the FBI the videos feature one man dropping off the backpack he was wearing at the scene of the explosion, only moments before the bombing took place. In the video the man is seen walking away from the bombing location soon after depositing the bag.

Meanwhile, the same video clip shows this man falling in behind another man also wearing a ball cap. The footage was captured roughly 15 minutes prior to the explosions at the Boston marathon finish line. Just enough time to get safely away from the blast.

FBI Reaches Out To Citizens For Help In The Boston Marathon Bombing Investigation

According to FBI spokesperson DesLauriers,

"We consider them to be armed and extremely dangerous. No one should approach them"

However DesLauriers of the FBI did encourage the public to call the FBI tip line in any information concerning the possible suspects was known.

"Somebody out there knows these individuals as friends, neighbors, co-workers or family members of the suspects ...though it may be difficult, the nation is counting on those individuals to come forward and provide [information] to us, no detail is too small. Each piece moves us forward towards justice."

The FBI takes great risk in posting the photos as they know it could make their job harder, forcing the possible suspects into hiding, but they are hoping with the release of the photos citizens will come through and help the FBI to find and apprehend these possible suspects.

Batteries, Pressure Cooker Lids, Circuit Boards and Other FBI Boston Marathon Bombing Clues

Additional clues concerning how the bombs were made and what was used to set them off have also emerged on Thursday as some sources are saying a circuit board and parts from a toy remote control vehicle were found and thought to be part of the Boston marathon bomb detonation device.

The FBI believes that at least one of the bombs was created from a pressure cooker which we have heard about for the last tow days, filled with materials that would wreak he most havoc and cause the greatest amount of injuries. Materials such as shrapnel, nails and ball bearing. A smashed pressure cooker lid was found on top of a building near the Boston marathon bombing site, and may have belonged to one of the bombs.

The FBI is also analyzing cellphone tower records in hopes of discovering possible signs of calls that may have been placed to trigger the explosions from a remote location.

As more details emerge concerning the FBI investigation of the Boston marathon bombing and possible suspects


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Update - Boston Marathon: 2 Possible Bombing Suspects, Ricin Letters, Casualties Identified And Other Investigation Developments

The Boston Marathon Investigation is finally picking up as two possible suspects in the Boston Marathon bombing are being looked according to recent reports. No arrests have yet been made in the Boston bombing case however. Suspects were identified through a Lord and Taylor video clip plus clips from other retail stores nearby. Keep reading for more information on the possible bombing suspects identified today.

In addition, today a ricin poison-laced letter tested positive at the White House, and a third victim of the Boston marathon explosions, Lu Lingzi, was identified. Though law enforcement officers have worked tirelessly to uncover clues and leads as to who is to blame for the explosions that took place at the Boston Marathon on Patriot's Day, until Wednesday afternoon, no solid leads had been found or arrests made.

This all changed, however, as new clues and evidence surfaced in the Boston Marathon bombing investigation and now it is believed that two suspects will be taken into custody based off of some retail store video clips which emerged. Here is the latest on the Boston Marathon bombings.

Boston Marathon Bombing Update 1: Two Possible Bombing Suspects Identified Wearing Backpacks

On Wednesday afternoon law enforcement officials stated that a possible bombing suspect had been identified and that a Boston arrest may be on the way. A Lord and Taylor video clip as well as other department store videos from the area were used to identify the possible bombing suspect. The clips show the possible suspect near the location where the second Boston Marathon explosion went off. Moments later however, sources for the Los Angeles Times claimed that two possible suspects have actually been found in the surveillance videos. Though the first clip we heard about today featured one man, authorities now believe a second video shows "two men with two backpacks."

Here is what the Los Angeles Times is reporting concerning the possible bombing suspects in the videos:

"U.S. counter-terrorism and law enforcement officials told The Times that the suspects in the Boston bombings were seen in a department store video that caught images of a man leaving a backpack near the finish line. A second federal official said he has been briefed that authorities believe a second video or photo showed "two men with two backpacks.

A counter-terrorism official said the suspects were picked out because they were carrying black backpacks, as well as because of their demeanor and how they reacted to the bomb blasts. That official said authorities do not yet know the identities of those in the videos. "

If true, this would signify a major break in the Boston marathon bombing investigation.

Though the local authorities had been searching tirelessly for clues, many were beginning to feel anxious as two days passed with no arrest. Investigators had reached out to the public asking for leads through video or photograph near the scene of the crime in hopes of finding something that would lead them to who was behind the Boston explosions. Monday and Tuesday night much buzz focused around a mysterious man on roof who some speculated could be connected to the bombing. Then Tuesday evening a photo of a suspicious bag surfaced near the finish line of the race.

Still nothing solid was found until this most recent Lord and Taylor video. The video shows the person in question carrying and possibly dropping a black bag outside the Forum restaurant on Boylston. A 5pm briefing will reveal what role the suspicious man may have played in the Boston Marathon Bombing.

Fox News is reporting that investigators have now arrested the first suspect and it is expected the young man will appear in federal court in Boston later today. At this point the person's name has yet to be divulged.

According to officials, this is "significant" progress in the case of the Boston Marathon bombing.

Boston Marathon Bombing Update 2: Ricin Poison-Laced Letter Sent to President Obama

A ricin poison laced letter arrived at the White House Tuesday which was identified as such on Tuesday after tests came back positive. Tough the idea of ricin poison being used as by assassins on a regular basis has been somewhat hyped by the media, the fact of the matter is it has rarely been used as such. That is until this week. Just one day after the tragic bombing which took place at the finish line of the Boston Marathon, the suspicious letter arrived at the White House, which tested positive for Ricin. So what is ricin poison? Well it is a substance that can be made from castor plant - the same from which castor oil is derived. There is no cure for the poison and it is deadly when inhaled. Though the FBI has stated that the letter appears not to be connected to the Boston Marathon bombing, still investigators will remain vigilant for any signs that the President could be in danger. In addition to the ricin laced letter that arrived at the White House, another poisoned letter was identified which was sent to Sen. Roger Wicker of Mississippi. Though roughly once a year a letter test positive for Ricin, two within one week is a somewhat odd occurrence.

Boston Marathon Bombing Update 3: Lu Lingzi, Third Casualty Identified.

Lu Lingzi, a Chinese graduate student at Boston University was identified Tuesday as the third victim of the 2013 Boston Marathon bombing.

So who was Lu Lingzi?

Lingzi was a Chinese graduate student, studying statistics at Boston University and was considered an outstanding student by all who knew her. Lu Lingzi's father was the one to identify and confirm his daughter death. Lu Lingzi graduated from a Shenyang high school and studied international trade at Beijing Institute of Technology. After that tie she applied to and was accepted at Boston University.

According to an official from the consulate press section, Lu Lingzi was not at the race alone. She along with two other Chinese friends, who were also students, were watching the race and stationed near the finis line. Though one of the three students escaped the blast free of injury another was harmed and the third, Lu Lingzi died. Lu is the third casualty to be identified in the April 15th Patriots Day bombings. On Tuesday evening, Boston University held a vigil to honor the memory of the victims, including alumnus Lu Lingzi.

In China as news arrived of Lu's death Chinese social-media reacted with sorrow. Just one hour after the news started to release concerning the Chinese casualty o the Boston bombing, 500 people had posted digital candles in her honor on Weibo. By the afternoon of April 17 the count reached over 8,000.

It is clear this attack on those present at the Boston marathon that day has had a far-reaching national and international effect. Thus far the number of casualties in Monday's Boston marathon bombings has reached 176 with 17 in critical condition. The casualties have remained at a steady three people. Those include an 8-year-old boy, a 29-year-old restaurant manager and Lin Lingzi. As the investigation into the Boston Marathon bombing continues we will keep you updated.

As the investigation into the Boston Marathon bombings continues we will keep you updated.