Xiao "Ben" Xiong Luo, the owner of the home on 2432 Moraga Avenue was killed after the robbers ransacked the house and tied up nine men and women in the basement..
A police source tells ABC7 News that the basement had been renovated into small rooms. Investigators are trying to find out if the home was being used for illicit activities such as prostitution or gambling.
They say no drug paraphernalia or marijuana growing equipment was found.
In recent years, police have raided homes in the Sunset District which have been used for prostitution and as pot growing farms.