Temperatures will be more than 20 degrees below normal throughout the Northeast, forecasters say.
Some have said that the mugshot of Charles Andrew Eldridge, who was arrested on charges unrelated to the murders, looks like a police sketch of a suspect.
A Baptist minister, King led the civil rights movement by peacefully pursuing a vision of racial justice. He was assassinated in 1968.
The TSA said unscheduled absences on Saturday reached 8 percent of its 51,000 officers, compared with 3 percent a year ago.
A former CIA technical operations officer who helped rescue six U.S. diplomats from Iran in 1980 and was portrayed by Ben Affleck in the film "Argo" has died.