The Federal Bureau of Investigation searched the Riverside County home of the brother of one of the shooters in the Dec. 2 San Bernardino attack, a law enforcement source close to the investigation said on Thursday.
The source said that investigators with a search warrant went to the Corona home of Syed Raheel Farook, a Navy veteran whose brother and sister-in-law, Syed Rizwan Farook and Tashfeen Malik, killed 14 people at a holiday party.
Officials are battling Apple in court to get the company to help them unlock an iPhone that had been used by one of the shooters.
The source said that investigators do not intend to make an arrest on Thursday. The source did not say whether the search was related to efforts to unlock the iPhone.
Syed Rizwan Farook and his wife died in a shootout with police the same day they attacked the holiday party.