CNN reports that officials have a 'pretty good idea' who Foley's killer is

Two U.S. officials have led CNN to believe that U.S. law enforcement may have identified James Foley's killer, who they believe is currently in Syria.

The official, who spoke on condition of anonymity, said they'd been using 'all means' to identify the masked man in the ISIS video, including voice analysis and metadata analyzation among other methods.

According to CNN's report, FBI agents believe the subject is tied to a group of extremists based in London.

Though the official cautioned that 'it's not 100 percent yet,' he said, 'they have a pretty good idea of who it may be.'

Authorities are reportedly still trying to determine whether the masked man speaking in the video of Steven Sotloff's death is the same knife-wielding militant in the Foley video, adding that it was 'too premature' to know.

[Slideshows below contain images of Foley's funeral as well as a mourning ceremony for Sotloff:]