. >> reporter: officials say farouk and his wife, tashfeen malik who came here from pakistan, were sharply focused this surveillance video, obtained by abc news, shows farouk at a california firing range, just days before the attack, practicing with the weapons he and his wife would use. >> 911. >> we have an active shooter here. >> ma'am, listen to me, take a deep breath. is he still shooting? >> oh, my gosh. >> reporter: farouk and his wife killed 14 of his fellow workers at the party and wounded 22 more. >> how many rounds did he fire? they posted a message on facebook, pledging alegion yanss to isis leader abu bakr al baghdadi. but officials say the couple actually had to conduct an listen search that very morning. who is the leader of isis. >> maybe they didn't know who it was. >> reporter: two lone wolves. who died in a fierce gun battle with police after killing so many. and the couple had more terror in mind. authorities say t l conference room. when they were stopped by police, they had been circling the neighborhood for hours, trying to remotely detonate those bombs and take more

malik, may have traveled. the problem? they don't have farook's four-digit password. the fbi believes that farook used apple's security option, basically a self-destruct mechanism, that renders all data on the phone permanently inaccessible if the proper code isn't entered after ten tries. but with 10,000 unique possibilities, the fbi knows impossible in just ten tries, and so it wants apple engineers to design software to break into the phone. in an impassioned statement, ceo tim cook said, "the government users. adding that the software is, quote, something we simply do consider too dangerous to create. the fight exploding on social media with presidential candidates weighing in. >> who do they think they are? no, we have to open it up. >> apple is standing firm arguing if they found a way to break into that phone they'll be able to break into any phone which could put the private data of millions of users at stake. manhattan's chief prosecutor tells us he alone is trying to open more than 150 encrypted ipho

malik, were shot dead in their black suv. but in between, officials said there is an 18-minute mystery, an unaccounted gap in their whereabouts not detected by >> we have accounted for three hours and 42 minutes of their time. we are missing 18 minutes of their time. >> reporter: and the fbi made a plea for the public's help to solve the mystery, showing pictures of their vehicle. >> we want to ensure that if they made contact with anyone that we don't already know about that we're able to fully investigate those matters. >> reporter: and the fbi also wants to know what happened to the hard drive removed from the killers' computer at their home the morning of the attack. the two were tracked to this san bernardino lake around 11:45 a.m. by the fbi. but a search by divers did not turn up the hard drive or any other evidence on the lake bottom. solving the 18-minute gap mystery is important for the fbi because agents believe that may be when the couple ditched the hard drive of their computer, the hard drive that could provide

. >> farouq and tashfeen malik had made their plans to attack well in advance. >> there's been a mass shooting in a community college in southern oregon. >> somehow, this has become >> gunfire ripping through this louisiana movie theater. >> a gunman opened fire. >> police exchanging gunfire with a man inside this colorado springs planned parenthood. >> horrific tragedy in charleston. >> these people were in church. >> dylann roof has been caught. >> we have no room for hate. we have to forgive. >> a historic moment set in motion by the killings. thousands gathered in selma to remember that day in 1965. >> it's become a very important day in my life. >> reporter: an ugly scene in baltimore. still searching for answers after the death of 25-year-old freddie gray. >> sandra bland's death in a texas jail is sparking outrage. >> police officer michael slager fires eight times at walter scott. >> he was my son. >> be on the lookout for two escapees from clinton county correctional facility. >> many comparing it to the plot of shawshank redemption. >> the massive manhunt finally over. >> an