An FBI dive team on Thursday began a search of Seccombe Lake Park, just a few miles away from the site of the San Bernardino mass shooting last week, ABC News reported.
An official briefed on the investigation told ABC News that the team is searching the area as a precaution and to ensure that no evidence was missed.
The official said investigators are not searching for any particular piece of evidence, but earlier reports indicated they may be searching for the shooters’ hard drive.
A senior official with knowledge of the investigation said the FBI received information that the shooters, Syed Farook and Tashfeen Malik, spent time at the lake. The official said the purpose of Thursday's search is to see if the two left or stored anything at the lake, which is approximately 2.5 miles north of the Inland Regional Center.
Farook and Malik killed 14 people and wounded 21 others when they opened fire at participants of a holiday party hosted by Farook's co-workers with the county health department.
More and more details have been emerging about the shooting and the couple in recent days. FBI Director James Comey said on Wednesday that the two may have married as a ploy to fool American immigration authorities.
He added that Farook and Malik had discussed jihad and martyrdom even before they became engaged, meaning they were radicalized as early as the end of 2013.
Earlier this week, the FBI said Farook and Malik were both radicalized "for quite some time" and hat taken target practice at Los Angeles-area shooting ranges, and once "within days" of the massacre.
It is believed Farook had contact with people from at least two terrorist organizations overseas, and investigators have also said Malik had pledged allegiance to the Islamic State (ISIS) group in a Facebook posting.