NEW : Police identify suspect as 47-year-old Chuang Li . ` ` This is a very difficult time , '' the company says . The attack happened on the office building 's fifth floor . It was not immediately clear if there were any other people in the building.
NEW : Police identify suspect as 47-year-old Chuang Li . `` This is a very difficult time , '' the company says . The attack happened on the office building 's fifth floor . One of the four people hospitalized suffered life-threatening wounds .