<PAGE>   1
                                                                     EXHIBIT 3.2

                              AMENDED AND RESTATED
                CERTIFICATE OF DESIGNATIONS, RIGHTS, PREFERENCES
            AND LIMITATIONS OF SERIES B CONVERTIBLE PREFERRED STOCK,
                         $10.00 PAR VALUE PER SHARE, OF
                    SECURITY ASSOCIATES INTERNATIONAL, INC.
PURSUANT TO SECTION 151 OF THE GENERAL CORPORATION LAW OF THE STATE OF DELAWARE


         SECURITY ASSOCIATES INTERNATIONAL, INC. (the "Corporation"), a
corporation organized and existing under the General Corporation Law of the
State of Delaware, does hereby certify:

         That pursuant to authority conferred upon the Board of Directors by the
Certificate of Incorporation, as amended, of the Corporation, and pursuant to
the provisions of Section 151 of the General Corporation Law of the State of
Delaware, said Board of Directors, by unanimous written consent executed July
20, 2001, without a meeting, adopted and approved a resolution amending and
restating the Certificate of Designations, Rights, Preferences, and Limitations
of Series B Convertible Preferred Stock, $10.00 par value per share, which
resolution is as follows:

         RESOLVED, pursuant to the authority expressly granted and vested in the
Board of Directors of the Corporation in accordance with the provisions of its
Certificate of Incorporation, as amended, the Board of Directors hereby
designates twenty thousand (20,000) shares of the Corporation's authorized and
unissued preferred stock, $10.00 par value per share, as Series B Convertible
Preferred Stock (the "SERIES B PREFERRED") which shall have the following
powers, designations, preferences, and relative participating, optional or other
special rights, and qualifications, limitations or restrictions:

         1. Rank. As to distributions upon liquidation, dissolution and
winding-up of the Corporation, the shares of Series B Preferred shall rank: (i)
pari passu with the Corporation's outstanding Series A Convertible Preferred
Stock, par value $10.00 per share ("SERIES A PREFERRED") and (ii) senior to (A)
the Corporation's Common Stock, par value $.001 per share ("COMMON STOCK") and
(B) any class or series of capital stock of the Corporation hereafter created
either specifically ranking by its terms junior to the Series B Preferred or not
specifically ranking by its terms senior to or on parity with the Series B
Preferred (collectively with the Common Stock, "JUNIOR SECURITIES"), in each
case, as to payment of dividends and as to distributions of assets upon
liquidation, dissolution or winding-up of the Corporation, whether voluntary or
involuntary.

         2. Voting Rights. Except as otherwise required by law or expressly
provided herein, each share of Series B Preferred shall entitle the holder
thereof to vote on all matters submitted to a vote of the stockholders of the
Corporation and to have the number of votes


<PAGE>   2

equal to the number of shares of Common Stock into which such share of Series B
Preferred is then convertible pursuant to the provisions hereof, at the record
date for the determination of stockholders entitled to vote on such matters, or
if no such record date is established, at the date such vote is taken or any
written consent of stockholders is solicited. Except as otherwise required by
law or expressly provided herein, the holders of shares of Common Stock, Series
A Preferred and Series B Preferred shall all vote together as a single class and
not as separate classes.

         3. Dividends and Distributions. In the event any dividend or other
distribution payable in cash or other property (including shares of Common
Stock) is declared on the Common Stock, each holder of shares of Series B
Preferred on the record date for such dividend or distribution shall be entitled
to receive on the date of payment or distribution of such dividend or other
distribution the same cash or other property which such holder would have
received if on such record date such holder were the holder of record of the
number of shares of Common Stock into which the shares of Series B Preferred
then held by such holder are then convertible (the "Participating Dividend").

         4. Participating Distributions: Liquidation; Company Sale. If (i) the
Corporation liquidates, dissolves or is wound up, voluntarily or involuntarily,
or (ii) the Corporation consolidates or merges into or with any other
corporation or corporations or any other entity or entities, or (iii) the
Corporation sells or transfers all or substantially all its assets, or (iv) a
majority of the then outstanding capital stock of the Corporation is sold in a
transaction, and in the case of clause (ii) hereof, such transaction results in
the stockholders of the Corporation immediately prior to the transaction
possessing less than fifty percent (50%) of the voting securities of the
surviving entity, or in the case of clause (iii) hereof, of the entity owning
such assets (a transaction described in clause (i) hereof being referred to as a
"LIQUIDATION" and a transaction described in clauses (ii), (iii) or (iv) hereof
being referred to as a "COMPANY SALE"), then, subject to the conversion right of
the Series B Preferred provided in Section 5, the holders of the shares of the
Series B Preferred shall be entitled to receive, before any distribution or
payment is made upon the Common Stock or any other Junior Securities, on a pari
passu basis with any payments or distributions to which holders of shares of the
Series A Preferred shall be entitled upon a Liquidation or Company Sale in
accordance with the amount payable with respect to each share of Series A
Preferred and Series B Preferred:

               (A) In the event of a Liquidation without a Company Sale: (i) the
         Stated Value, plus, (ii) if after the payment of the Stated Value,
         there are any remaining assets and funds of the Corporation, such
         assets and funds shall be distributed to holders of the Series B
         Preferred, the Series A Preferred and the Common Stock, ratably, on
         the basis that all shares of the Series B Preferred and the Series A
         Preferred are deemed to have been converted into Common Stock in
         accordance with the terms hereof or thereof (provided that any amounts
         payable in respect of the Series B Preferred under this subparagraph
         (A)(ii) shall be reduced by the amounts paid in respect of the Series B
         Preferred under subparagraph (A)(i) above); or


                                       2
<PAGE>   3

               (B) In the event of a Company Sale, the higher of (i) the amount
         specified in subparagraph (A) above and (ii) the amount determined by
         dividing (x) the total consideration paid or payable in respect of the
         Company Sale, whether such consideration is in the form of cash, notes,
         earn-out payments, securities or other property of any kind whatsoever,
         by (y) total number of shares of Common Stock on the basis that all
         shares of the Series B Preferred and the Series A Preferred are deemed
         to have been converted into Common Stock in accordance with the terms
         hereof and thereof.

         For purposes hereof, the "STATED VALUE" shall equal the sum of (i) two
hundred fifty dollars ($250.00) per share of Series B Preferred, such amount to
be adjusted to reflect stock splits, stock dividends, subdivisions, combinations
or reclassifications which occur subsequent to the date hereof, plus (ii) in the
event that the Corporation shall have declared but not paid a dividend or other
distribution on its Common Stock (other than a dividend payable in shares of
Common Stock or in rights, options, warrants or convertible securities
containing the right to subscribe for or purchase shares of Common Stock), the
same cash or other property which a Series B Preferred holder would have
received if on the record date for the dividend or distribution such holder were
the holder of record of the number of shares of Common Stock into which the
shares of Series B Preferred then held by such holder are then convertible.

         From and after the date of a Liquidation or Company Sale, all rights of
the holders of any shares of the Series B Preferred, as such, shall cease and
terminate, such shares shall no longer be outstanding and shall automatically be
canceled and retired and shall cease to exist, and no consideration shall be
delivered or deliverable in exchange therefor other than the payments provided
for herein.

         If, upon a Liquidation or Company Sale, the assets shall be
insufficient to permit the payment to the holders of the Series A Preferred and
the holders of the Series B Preferred of the full preferential amount aforesaid
due them, all of the assets of the Corporation available for distribution to the
holders of the Series A Preferred and the holders of the Series B Preferred
shall be distributed ratably to the holders the Series A Preferred and the
holders of the Series B Preferred in accordance with the amount payable with
respect to each such share.

         5. Conversion.

            (a) Conversion Procedure.

                (1) Any holder of shares of Series B Preferred may at any time,
upon written notice to the Corporation, convert all or any number of such shares
held by such holder ("OPTIONAL CONVERSION") into a number of fully paid and
non-assessable shares of Common Stock equal to the then in effect Conversion
Ratio, as defined below, multiplied by the number of shares of Series B
Preferred being converted. At the time of Optional Conversion, the Corporation,
to the extent it has funds legally available therefor, shall pay in cash to such
holder of Series B Preferred then being converted an amount equal to all accrued
and unpaid Participating Dividends to the date of such Optional Conversion on
such



                                        3
<PAGE>   4

Converted Shares. In the event of an Optional Conversion, the Corporation shall
forthwith transmit to such holder of Series B Preferred upon surrender of the
certificate(s) representing such shares, stock certificates for the shares of
Common Stock issued as a result thereof, dated the date of Optional Conversion,
and such holder shall be deemed for all purposes to be the holder of such Common
Stock as of the date of Optional Conversion.

                (2) Initially each share of Series B Preferred shall be
convertible into one hundred (100) shares of Common Stock (the "CONVERSION
RATIO"). In the event of any split, stock dividend, subdivision, combination or
reclassification of shares of Common Stock, or other recapitalization of the
Corporation, having the effect of increasing or decreasing the issued and
outstanding Common Stock held by each holder thereof, the Conversion Ratio shall
be adjusted so that the number of shares of Common Stock into which each share
of Series B Preferred may be converted is equal to that number of shares of
Common Stock that represents the same proportionate ownership interest in the
Corporation as would have resulted if the conversion had taken place immediately
prior to the event causing such adjustment.

                (3) As soon as practicable after the date of conversion (but in
any event within ten (10) business days following surrender of certificates
representing the shares of Series B Preferred that have been or are to be
converted), the Corporation will deliver to the converting holder:

                    (A) a certificate or certificates representing the number of
whole shares (cash shall be paid in lieu of fractional shares) of Common Stock
issuable by reason of such conversion registered in such name or names (subject
to applicable securities laws and regulations) and in such denomination or
denominations as the converting holder has specified;

                    (B) payment, from funds legally available therefor, in an
amount equal to all Participating Dividends declared, unpaid and owing pursuant
to Section 3 hereof with respect to each share converted which have not been
paid prior to the date of conversion plus cash for all fractional shares; and

                    (C) a certificate representing any shares of Series B
Preferred (including fractional shares) which were represented by the
certificate(s) delivered to the Corporation in connection with such conversion
but which were not converted.

                (4) If for any reason the Corporation is unable to pay any
Participating Dividends declared, accrued, unpaid and owing pursuant to Section
3 on the shares of Series B Preferred being converted, the Corporation will pay
such Participating Dividends to the converting holder, plus interest on the
unpaid dividends for the period in excess of thirty (30) days during which such
dividends shall remain unpaid, calculated at the rate of 18% per annum, to the
converting holder as soon thereafter as funds of the Corporation are legally
available for such payment, with accrued and unpaid payments to be made in the
order in



                                       4
<PAGE>   5

which they accrued. At the request of any such converting holder, the
Corporation will provide such holder with written evidence of such obligation.

            (b) Authorization and Issuance of Common Stock. The Corporation
covenants and agrees that:

                (1) The Corporation will at all times reserve and keep available
out of its authorized but unissued shares of Common Stock, solely for the
purpose of issuance upon the conversion of the Series B Preferred as provided in
this Section 5, such number of shares of Common Stock as shall then be issuable
upon the conversion of all outstanding shares of Series B Preferred. The
Corporation covenants that all shares of Common Stock which shall be so issuable
shall, when issued, be duly and validly issued, fully paid and nonassessable and
free from all taxes, liens and charges. The Corporation will take all such
actions as may be necessary to assure that all shares of Common Stock may be so
issued without violation of any applicable law or regulation or any requirements
of any domestic stock exchange or market upon which any shares of Common Stock
may be listed.

                (2) The Corporation will not take any action which results in
any adjustment of the number of shares of Common Stock issuable upon conversion
of a share of Series B Preferred if the total number of shares of Common Stock
issuable upon conversion of the Series B Preferred then outstanding, together
with the total number of shares of Common Stock then outstanding and the total
number of shares of Common Stock reserved for any purpose other than issuance
upon conversion of Series B Preferred, would exceed the total number of shares
of Common Stock then authorized by the Corporation's Certificate of
Incorporation, as amended.

                (3) The issuance of certificates for shares of Common Stock upon
conversion of shares of Series B Preferred will be made without charge to the
holders of such shares of Series B Preferred for any issuance tax in respect
thereof.

                (4) The Corporation will not close its books against the
transfer of shares of Series B Preferred or of Common Stock issued or issuable
upon conversion of shares of Series B Preferred in any manner which interferes
with the timely conversion of shares of Series B Preferred.

            (c) Reorganization, Reclassification, Consolidation, Merger or Sale.
Any capital reorganization, reclassification, consolidation, merger or sale of
all or substantially all of the Corporation's assets to another person or entity
which is effected in such a way that holders of Common Stock are entitled to
receive (either directly or upon subsequent liquidation) stock, securities or
assets with respect to or in exchange for Common Stock is referred to herein as
an "ORGANIC CHANGE." Prior to the consummation of any Organic Change, the
Corporation will make appropriate provisions to insure that each of the holders
of Series B Preferred will thereafter have the right to acquire and receive such
shares of stock, securities or assets as such holder would have received if such
holder had converted the Series B Preferred immediately prior to such Organic
Change. The Corporation will not




                                       5
<PAGE>   6

effect any consolidation, merger or sale, unless prior to the consummation
thereof, the successor entity resulting from consolidation or merger or the
entity purchasing such assets assumes the obligation to deliver to such holder
of Series B Preferred such shares of stock, securities or assets as, in
accordance with the foregoing provisions, such holder may be entitled to
acquire.

            (d) Notices.

                (1) The Corporation will give written notice to all holders of
shares of Series B Preferred as soon as practicable but in any event at least
ten business days prior to the date on which the Corporation closes its books or
takes a record on with respect to any dividend or distribution upon Common Stock
or upon any other class of the Corporation's capital stock or with respect to
any proposed Organic Change.

                (2) Any notice required by the provisions of this Certificate of
Designations to be given to the Corporation or any holder of shares of Series B
Preferred shall be deemed given upon the first to occur of: (x) the date when
personally delivered to such holder of; (y) on the first business day following
the date on which it was delivered properly addressed to the agent of a
reputable commercial overnight delivery service; or (z) five (5) business days
after the same has been deposited properly addressed in the United States mail,
certified or registered mail, return receipt requested, postage prepaid.

            (e) Taxes and charges. The Corporation will pay all taxes and other
governmental charges, if any, that may be imposed in respect of the issuance or
delivery of shares of Common Stock upon conversion of shares of Series B
Preferred.

         6. Amendment. Except if a higher threshold is established by the terms
hereof, any of the terms of the Series B Preferred may be amended or waived if
the Corporation has obtained the affirmative vote of or written consent by the
holders of a majority of the shares of Series B Preferred then outstanding,
voting as a separate class.



         This Certificate of Designations, Rights, Preferences and Limitations
of Series B Preferred herein certified has been duly adopted in accordance with
the provisions of Section 151 of the General Corporation Law of the State of
Delaware.

                                             Signed on July 20, 2001

                                             /s/ James P. Arndt
                                             -----------------------------------
                                             James P. Arndt, Assistant Secretary



                                       6