On February 16, a California judge ordered Apple to help the FBI break into the Farook's phone despite Apple's resistance.
"The particular legal issue is actually quite narrow. The relief we seek is limited and its value increasingly obsolete because the technology continues to evolve," Comey said Sunday in a post on the Lawfare blog.
He added that FBI needs to unlock the phone in order to be able to "look the survivors in the eye, or ourselves in the mirror" since it could hold clue to finding more terrorists.
"We don't want to break anyone's encryption or set a master key loose on the land. I hope thoughtful people will take the time to understand that," Comey pointed out.
Apple's stance has been publicly supported by such tech giants as Google, Facebook and Twitter.