Delete from database using repeater that has checkboxes when checked delete

protected void ButtonDeleteAttachments_Click(object sender, EventArgs e)
        {
            var db = new knowitCVdbEntities();
            SPWeb theSite = SPControl.GetContextWeb(Context);
            SPUser theUser = theSite.CurrentUser;
            string strUserName = theUser.LoginName;

            var theEmpDocumentRem = (
                                        from p
                                            in db.EMPLOYEES
                                        where p.username == strUserName
                                        select p).FirstOrDefault();

            _emp = theEmpDocumentRem;

            if (_emp != null)
            {

                int docId = Convert.ToInt32(LabelDocumentID.Text);

                var documentList = (from p in db.EMPLOYEE_DOCUMENT
                                    where p.employee_id == _emp.employee_id && p.document_id== docId
                                    select p).ToList();

                foreach (var doclist in documentList)
                {

                    db.DeleteObject(doclist);
                    db.SaveChanges();


                }

                foreach (var docItems in RepeaterDocument.Items)
                {
                    if(_chk.Checked)
                    {
                        db.DeleteObject(docItems);
                    }
                    
                }

            }