[UPDATE BELOW] Multiple outlets are reporting that authorities have identified a suspect in connection with the Boston Marathon bombings. The Associated Press reports that a suspect is already in custody and a source tells CNN an arrest has been made. But CBS says no arrest. According to CNN, "the breakthrough came from analysis of video from a department store near the site of the second explosion. Video from a Boston television station also contributed to the progress."

An unidentified official who was briefed on the Boston Marathon bombing investigation tells the Boston Globe that "authorities have an image of a suspect carrying, and perhaps dropping, a black bag at the second bombing scene on Boylston Street, outside of the Forum restaurant." The AP says the suspect is being brought to federal court, but none of this has been officially confirmed; it's all anonymous sources. We'll update as more verified information becomes available.

Update 2:57 p.m.: It looks like the AP and CNN got burned by a source. Both outlets are walking back reports of arrest. CNN now says, "There is conflicting information as to whether someone has been arrested in connection with the Boston Marathon bombings. A federal law enforcement source told CNN's Fran Townsend that someone was arrested. But later, two senior administration officials and another federal official told Townsend that there had been a misunderstanding among officials and that no one has been arrested."

The Boston Police Department insists no arrest has been made. Following the AP report about a suspect was being taken into custody, media swarmed the federal courthouse. Now the AP reports, "The official who spoke to the AP did so on condition of anonymity and stood by the information even after it was disputed. The official, who was not authorized to divulge details of the investigation, had said the suspect was expected in federal court in Boston."

But it still seems that investigators have identified a suspect. CBS is now reporting: "Man sought as possible suspect is WHITE MALE, wearing white baseball cap on backwards, gray hoodie and black jacket." Investigators identified the suspect based on two videos taken before Monday's attack, sources say. The FBI will hold a press conference at 5 p.m., so we expect to get some official clarification at that time.

Update 3:23 p.m.: The Federal Court and Brigham & Women's Hospital have been evacuated for reasons which remain unclear—some people inside the buildings were told it was a bomb threat, others said fire drill. The hospital was quickly given the all-clear when, according to the Boston Globe, it was determined that the cause of the alarm was a "man left locked car at valet. Gas cans in back, according to official source."

Update 4:33 p.m.:

All clear over at the Federal Courthouse. We know this because a man came outside and waved a giant green flag around. Unfortunately, they've

cancelledpostponed

the 5 p.m. press conference. But sources tell CNN that investigators want to question a man seen on video as a possible suspect in the attack. (Of course, you know how these SOURCES can be—see above.)