( CNN ) -- A Yale lab technician charged in the strangling murder of a Yale graduate student less than a week before she was to be married plans to plead guilty , his attorney said Wednesday . Public defender Joseph Lopez said his client , Raymond Clark III , will plead guilty in New Haven , Connecticut , Superior Court on Thursday as part of a plea bargain , though he would not divulge the details of the agreement . Clark had originally pleaded not guilty in January 2010 . Clark , 26 , of Branford , Connecticut , is accused in the slaying of Annie Le , 24 , who was pursuing a doctorate in pharmacology at Yale when she went missing September 8 , 2009 . Le 's body was discovered inside a wall of a Yale lab building four days later after an extensive search by the FBI and police . She had planned to marry Columbia graduate student Jonathan Widawsky on the day her body was found . Clark was not a Yale student but had worked as a lab technician at the university since 2004 , after graduating from high school . He lived with his girlfriend , who also is a Yale lab technician , according to police . A Yale faculty member described Clark 's job as maintaining colonies for animals used in research . A motive in Le 's killing was unclear , but police said they were treating the case as workplace violence . Calls to the New Haven district attorney 's office and Yale University seeking comment were not immediately returned Wednesday .
Raymond Clark III will enter a guilty plea Thursday , the public defender says . There is a plea agreement , the attorney says , but he does not divulge details . Yale graduate student Annie Le 's body was found inside a wall at a Yale lab building .