Authorities have identified the two suspects involved in the San Bernardino massacre on Wednesday, the deadliest U.S. mass shooting since the Sandy Hook killings in 2012.

The Washington Post reports U.S.-born Syed Rizwan Farook, 28, and his Pakistani-born wife, Tashfeen Malik, 27, were responsible for the office holiday party rampage in San Bernardino, California that left 14 dead and at least 17 wounded.

NBC Los Angeles released an image of the suspect Farook on their Twitter account.

According to investigators, the couple stormed into the conference center donning black masks and tactical gear, armed with handguns and assault rifles. They were later gunned down in a shootout with police.

Authorities are searching for a possible motive for the shooting.

"I don't think they grabbed the guns and tactical gear on a spur-of-the-moment thing," San Bernardino Police Chief Jarrod Burguan said hours after the incident.

The suspects' family said that the couple had dropped off their 6-month-old daughter with Farook's mother, claiming to have a doctor's appointment.

Later, Farook attended an office party conducted by the San Bernardino County Department of Public Health, where he once worked as an inspector. Details about what happened at the gathering remain unclear, but sources indicate Farook left the party in an angry or agitated manner.

According to NBC News, 10 to 30 minutes passed before Farook returned with his wife Malik and started shooting.

The pair attempted to escape in a black SUV, but were spotted two miles from the scene. An ensuing shootout with police left both suspects dead.

"These people came prepared to do what they did as if they were on a mission," Burguan said. "They were armed with long guns, not with handguns."

Farook's brother-in-law Farhan Khan said he was shocked that Farook would do this.

"I just cannot express how sad I am for what happened today," Khan said at a Wednesday press conference held by the Council on American-Islamic Relations, a Muslim advocacy g

roup. "I am in shock that something like this could happen."

Investigators are not ruling out terrorism as a motive.

U.S. Attorney General Loretta Lynch spoke on the incident at a separate White House event on incarceration and poverty, Reuters reports.

"Whatever the results of this investigation ... one thing is clear: Violence like this has no place in this country," she said.

President Barack Obama announced on Thursday from the Oval Office that the FBI would be taking over the investigation.

"At this stage we do not yet know why this terrible event occurred," Obama said. "It is possible this was terrorist-related ... it is possible this was workplace-related."

The president also reiterated previous statements that lawmakers needed to come together to implement stricter gun control laws.

"We need to make sure when individuals decide they want to do harm we make it harder because right now it's just too easy," he said.