(CNN) — On Wednesday, a law enforcement official who is being regularly briefed on the investigation into the fatal bombings at the Boston Marathon told CNN’s Susan Candiotti that images showing two men near the marathon finish line were being circulated to state and federal law enforcement agencies. The source described the men as “possible suspects.”
But a source told CNN’s Deb Feyerick on Thursday that those individuals are no longer of high interest to investigators.
The men faced scrutiny and were considered potentially important to the case because one of them had been carrying a black backpack close to one of the bombing sites.
Asked about the images at a congressional hearing Thursday, Homeland Security Secretary Janet Napolitano urged caution.
“There is some video that has raised the question of those that the FBI would like to speak with,” she said. “I wouldn’t characterize them as suspects under the technical term. But we need the public’s help in locating these individuals.”
She said the investigation is “proceeding apace.”
But she said, “This is not an ‘NCIS’ episode. Sometimes you have to take time to properly put the chain together to identify the perpetrators, but everyone is committed to seeing that that gets done in the right way.”
Earlier Wednesday, two sources with knowledge of the investigation identified a man as a possible suspect in the attack but did not name him.
Seen on a video, the man wore a white baseball cap. One of the sources added that the cap was on backward and the man was also wearing a light-colored hooded sweatshirt and a black jacket.
It was not immediately clear if he is one of those alluded to in the photographs distributed to law enforcement officials.
The reports came after a chaotic day in which some law enforcement sources initially told media outlets that a suspect had been arrested, only to have the FBI and Boston police issue formal denials that any suspect was in custody.
Patrick urged patience to allow investigators space to do their job.
“I wish they had nailed the perpetrator within minutes of this catastrophe, but I understand from experience it’s going to take some time,” he said.