Who deleted the data and commited

SELECT NAME, value FROM v$parameter WHERE NAME LIKE 'audit%';
SQL> SELECT NAME, value FROM v$parameter WHERE NAME LIKE 'audit%';
NAME
----------------------------------------------------------------------
VALUE
----------------------------------------------------------------------
audit_sys_operations
FALSE
audit_file_dest
E:\ORACLE\PRODUCT\10.2.0\ADMIN\XP10R2JAN\ADUMP
audit_trail
DB
The audit is being done to the DB
SQL> desc dba_audit_trail;
SELECT userid, action#, STATEMENT, OBJ$NAME, To_Char (timestamp#, 'mm/dd/yyyy hh24:mi:ss')
FROM sys.aud$ ORDER BY timestamp# asc;