In an effort to put a name to the person or persons behind Monday’s deadly finish line bombing, which injured more than 170 people and killed three, the FBI has released Boston Marathon bombing suspect photos to the public at a 5 p.m. press briefing Thursday, April 18. The bombing suspect photos were gleaned from department store surveillance footage and television newscast footage taken from the blast scene.

Below are the Boston Marathon bombing suspect photos released by the FBI, depicting suspect number one (dark baseball cap) and suspect two (white baseball cap).

Additionally, here is a surveillance video released by the FBI, depicting both suspect number one and suspect number two walking in tandem along Boylston Street:

As the FBI continues to work on developing additional images, they are asking the public to send any and all tips to, or call 1-800-CALL-FBI (1-800-225-5324).

Prior to the 5 p.m. press briefing, FOX 25 Boston released a photo, telling viewers that they had blurred out the faces around the alleged suspect out of respect, because “those are the victims.” The suspects were allegedly attempting to appear separate while operating as a team, “hiding in plain sight,” according to FOX 25 Boston.

Earlier this morning, Homeland Security Secretary Janet Napolitano told the House Homeland Security Committee that “there is some video that raised the question” of specific individuals the FBI would like to interview, according to CBS Boston.

“Every hour we’re closer,” Massachusetts Gov. Deval Patrick told CNN on Wednesday. “And I say that because we’ve got the very best professionals at every level working this. And working it hard.”

According to Fox News, citing a reporter who has seen the photos in question and called them “clear,” “one of the men has a backpack that appears to match the bag believed to have been used in the attack. The other man also appears to have a bag of some kind.”

For complete coverage of the Boston Marathon bombings day by day, please click here for Tuesday’s news, here for Wednesday, and here for everything we’ve learned so far today.