1. Name and Address of Reporting Person ACKERMAN, THOMAS F. 251 Ballardvale Street Wilmington, MA 01887 USA 2. Issuer Name and Ticker or Trading Symbol Charles River Laboratories Int'l., Inc (CRL) 3. IRS or Social Security Number of Reporting Person (Voluntary) 4. Statement for Month/Year 5/2002 5. If Amendment, Date of Original (Month/Day/Year) 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) ( ) Director ( ) 10% Owner (X) Officer (give title below) ( ) Other (specify below) Sr. Vp and CFO 7. Individual or Joint/Group Filing (Check Applicable Line) (X) Form filed by One Reporting Person ( ) Form filed by More than One Reporting Person TABLE I -- Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned +---------------------------------+----------+-------------+-----------------------------+----------------+-----------+------------+ |1. Title of Security |2. Trans- |3. Trans- |4. Securities Acquired (A) |5. Amount of |6. Owner- |7. Nature | | | action | action | or Disposed of (D) | Securities | ship | of In- | | | Date | Code | | Beneficially | Form: | direct | | | | | | Owned at | Direct | Bene- | | | (Month/ | | | End of | (D) or | ficial | | | Day/ +-------+-----+-----------+------+----------+ Month | Indirect| Owner- | | | Year) |Code |V |Amount |A/D |Price | | (I) | ship | +---------------------------------+----------+-------+-----+-----------+------+----------+----------------+-----------+------------+ Common Stock 05/02/2002 S-6000 D $33.1500 19767 D TABLE II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned +-------------+--------+----------+---------+-----------+---------------------+----------------+----------+--------+-------+-------+ |1. |2. |3. |4. |5. |6. |7. |8. |9. |10. |11. | | | | | | | | | |Number |Owner- | | | | | | | | | | |of |ship | | | | | | | | | | |Deriv- |Form of| | | | | | | | |Title and Amount| |ative |Deriv- | | | | | | | | |of Underlying | |Secur- |ative |Nature | | |Conver- | | |Number of | |Securities | |ities |Secur- |of | | |sion or | | |Derivative |Date Exercisable +-------+--------+ |Benefi- |ity: |In- | | |Exercise| | |Securities |and Expiration Date | |Amount | |cially |Direct |direct | | |Price of|Transac- |Transac- |Acquired(A)|(Month/Day/Year) | |or | |Owned |(D) or |Bene- | |Title of |Deriv- |tion Date |tion Code|Disposed(D)+----------+----------+ |Number |Price of |at End |In- |ficial | |Derivative |ative |(Month/ +------+--+-----+-----+Date Exer-|Expira- | |of |Derivative|of |direct |Owner- | |Security |Security|Day/Year) |Code |V |(A) |(D) |cisable |tion Date |Title |Shares |Security |Month |(I) |ship | +-------------+--------+----------+------+--+-----+-----+----------+----------+-------+--------+----------+--------+-------+-------+ Explanation of Responses: SIGNATURE OF REPORTING PERSON /s/ THOMAS F. ACKERMAN DATE 06/04/2002 This trade occured pursuant to a rule 10b5-1 trading plan established December 2001.