"We're trying to sort through all the information to secure the truth," Qiaojing Ella Zheng, senior counsel at Sanford Heisler Sharp, told CNBC on Monday.
Sanford Heisler Sharp represents the family of Qin Chen, the Facebook employee who committed suicide at the company's Menlo Park, California, headquarters on Sept. 19. Zheng said the firm has spoken with community members and has met with Facebook and its attorneys.
Sanford Heisler Sharp is currently running ads on Facebook that are being shown to users in California encouraging anyone with information about the death to reach out.
"We're looking for anybody who might have relevant information," Zheng said. "That could be Facebook employees or community members. Anyone with information we welcome them to contact us."
Facebook confirmed Chen's death was a suicide in a statement after numerous people gathered outside the company's headquarters on Thursday to demand "justice for Qin."
Facebook declined to comment on the Sanford Heisler Sharp investigation. There are rumors that Qin may have endured bullying at Facebook, said Bill Young, who was one of the volunteers that organized the protest. However, Young was not an employee, and he said most of the protesters were not Facebook employees either.
"We are saddened by the tragic news that we lost one of our employees, Qin Chen, to suicide last week at our Menlo Park headquarters," a Facebook spokeswoman said in a statement. "And, we are doing everything we can to support his family and loved ones during this time."