LOS ANGELES — Specialized divers with the FBI searched a San Bernardino lake for a second day Friday, looking for a computer hard drive and any other evidence linked to last week’s terror attack and the husband-and-wife shooters who killed 14 people.

Investigators have said the killers tried to cover their tracks by destroying emails, cellphones and other items at their home in Redlands. They were tipped that the small lake in a park about 3 miles from the terror attack might hold the hard drive, according to a law enforcement official.

The search began Thursday after authorities learned the shooters, Syed Rizwan Farook, 28, and Tashfeen Malik, 29, may have been in the area the day of the attack, said David Bowdich, chief of the FBI’s Los Angeles office. He said the search could last several days.

Farook, a U.S. citizen, and his Pakistani-born wife, opened fire Dec. 2 at a holiday luncheon attended by many of Farook’s co-workers in the San Bernardino health department. The couple died in a shootout with law enforcement hours after the attack, leaving behind a 6-month-old daughter.

Authorities say Farook and Malik, who came to the U.S. on a fiancee visa in July 2014 and married her husband the next month, were not known to law enforcement before the shootings. But since the attack they have determined the couple discussed martyrdom and jihad online as early as 2013.

Farook’s longtime friend and relative-through-marriage, Enrique Marquez, bought the assault rifles used in the shooting more than three years ago, about the time he converted to Islam, according to the law enforcement official. Farook asked Marquez to buy the rifles because he was worried he wouldn’t pass the background check himself. Marquez told investigators that he and Farook were plotting an attack in 2012.

Idaho Sen. Jim Risch, a Republican who sits on the Senate Select Committee on Intelligence, said they had an actual plan, including buying weapons, but became apprehensive and shelved it because of law enforcement activity and arrests in the area.