After days of combing through huge amounts of photographic and video evidence of Monday's bombings at the Boston Marathon, authorities have two clear video images of suspects that they plan to release to the public Thursday afternoon.

The Boston Globe, citing an unnamed official who has been briefed on the case, is reporting that the images are of two men carrying black bags, one at each of the explosion sites. It is unclear why the images have not been released yet.

Thursday morning, President Obama is attending an interfaith memorial service at Boston's Cathedral of the Holy Cross. While in Boston, Obama will also meet with families of the victims and first responders, many of whom immediately ran toward the blast sites to help aid those who were wounded, many grievously, by the twin pressure-cooker bombs that were packed with shrapnel.

The explosions injured 176 and killed three people: Martin Richard, who was just 8 years old; Krystle Campbell, 29; and Lu Lingzi, a Chinese graduate student at Boston University.

Also speaking at the memorial service are Boston Mayor Thomas Menino, Massachusetts Governor Deval Patrick, Cardinal Sean O'Malley, and numerous other religious and community leaders.

More From Cars 108