<PAGE>

                                                                   Exhibit 3.96


                              CERTIFICATE OF MERGER

                                       of

                       EXCELLENCE IN TRAINING CORPORATION
                              (in Iowa corporation)
                                  with and into
                 PROFESSIONAL SECURITY TELEVISION NETWORK, INC.
                            (a Delaware Corporation)


     Pursuant to the provisions of Section 252 of the Delaware General
Corporation Law (the I DGCLII) , and Section 490. 1101 of the Iowa Business
Corporation Act, Professional Security Television Network, Inc., a Delaware
corporation ("PSTNII), and Excellence in Training Corporation, an Iowa
corporation ("ETC") do hereby adopt the following Certificate of Mcqcr for the
purpose of merging ETC with and into PSTN:

     1.   The name and state of incorporation of each of the constituent
          corporations are:

                 NAME OF                                         STATE OF
                 CORPORATION                                     INCORPORATION

                 Professional Security
                 Television Network, Inc.                        Delaware

                 Excellence in Training
                 Corporation                                     Iowa

2. An agreement of merger (the "Merger Agreement") has been approved, adopted
certified, executed and acknowledged by each of the constituent corporations in
accordance with the provisions of Section 252 of the DGCL providing for the
combination of ETC and PSTN and resulting in PSTN being the surviving
corporation.

3.   The name of the surviving corporation shall be Professional S@ty Television
     Network, Inc.

4.   The Certificate of Incorporation of PSTN shall be the Certificate of
     Incorporation of the surviving corporation,
<PAGE>

which is hereby amended as follows:

     A. The Title of the Certificate of Incorporation is hereby amended in its
entirety to read as follows:

                          Certificate of Incorporation
                                       Of
                       Excellence in Training Corporation

     B. The first article of the Certificate of Incorporation is hereby amended
in its entirety to read as follows:

     FIRST: The name of the Corporation is Excellence in Training Corporation.

                               STATE OF DELAWARE
                               SECRETARY OF STATE
                                 OF CORPORATIONS
                            FILED 12:30 PM 12/12/1990
                               903465321 - 2249188

                          CERTIFICATE OF INCORPORATION
                                       OF
                  PROFESSIONAL SECURITY TELEVISION NETWORK INC.

I, the undersigned natural person acting as an incorporator of a corporation
(hereinafter called the "Corporation") under the General Corporation Law of the
State of Delaware, do hereby adopt the following Certificate of Incorporation
for the Corporation;

FIRST: The name of the Corporation is Professional security Television Network,
Inc.

SECOND: Trio registered office of the Corporation in the state of Delaware is
located at Corporation Trust Center, 1209 Orange Street, in the City of
Wilmington, county of New Cattle, The name of registered agent of the
Corporation at such address in The Corporation Trust Company.

THIRD: The purpose for which the corporation is organized is to engage in in any
and all lawful acts and activity for which corporations may be organized under
the General Corporation Law of Delaware. The Corporation will 
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have perpetual existence

FOURTH: The total number of shares of Stock which the Corporation shall have
authority to issue in $1,000 shares, par value $.0l per share, designated Common
Stock.

FIFTH: The name of the incorporator of the Corporation is Annette Beebe, and the
mailing address of such incorporator is Founders Square, Suite 100, 900 Jackson
Street, Dallas, Texas 75202-4499.

SIXTH: The number of directors constituting the initial board of directors is
one, and the name and mailing address of the person who is to serve as director
until the first annual meeting of stockholders or until his successor is elected
and qualified are Carl Wastcott, 1303 Marsh Lane, Carrollton, Texas 75006.

SEVENTH:  Directors of the Corporation need not he elected by written
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disposition Co the maximum extent permitted under the Delaware General
Corporation Law, as the same exists or may hereafter be amended. if a claim for
indemnification or advancement of expenses hereunder is not paid in full by the
Corporation within sixty (60) days after a written claim has been received by
the Corporation, the claimant may at any time thereafter bring suit against the
Corporation to recover the unpaid amount of the claim, and if successful in
whole or in part, the claimant shall also be entitled to be paid the expenses of
prosecuting such claim. It shall be a defense to any such action that such
indemnification or advancement of costs of defense are not permitted under the
Delaware Moral Corporation Law, but the burden of proving such defense shall be
on the Corporation. Neither the failure of the Corporation (including its board
of directors or any committee thereof, independent legal counsel, or
stockholders) to have made its determination prior to the commencement of such
action that indemnification of, or advancement of costs of defense to, the
claimant in permissible in the circumstances nor an actual determination by the
Corporation (including its board of directors or any committee thereof,
independent legal counsel, or stockholders) that such indemnification or
advancement is not permissible shall be a defense to the action or create a
presumption that such indemnification or advancement is not permissible. In the
event of the death of any person having a right of indemnification under the
foregoing provisions, such right shall inure to the benefit of his or her heirs,
executors, administrators, and personal representatives. The rights conferred
above shall not be exclusive of any other right which any person may have or
hereafter acquire under any statute, by, air, resolution of stockholders or
directors, agreement, or otherwise.

     The Corporation may additionally indemnify any employee or agent of the
Corporation to the fullest extent permitted by law.

     As used herein, the term "proceeding" means any threatened, pending, or
completed action,
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suit, or proceeding, whether civil, criminal, administrative, arbitrative, or
investigative any appeal in such an action, suit, or proceeding, and any inquiry
or investigation that could lead to such an action, suit, or proceeding.

     ELEVENTH: A director of the corporation shall not he personally liable to
Corporation or its stockholders for monetary damages for breach of fiduciary
duty as a director, except for liability (i) for any breach of the directors
duty of loyalty to
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ballot unless the by-laws of the Corporation otherwise provide.

EIGHT: The directors of the Corporation shall have the power to adopt, amend,
and repeal the by-laws of the Corporation.

NINTH: No contract or transaction between the Corporation and one or more of its
directors, officers, or stockholders or between the Corporation and any person
(as used herein "person"
<PAGE>

means other corporation, partnership, association, firm, trust, joint venture,
political subdivision, or instrumentality) or other organization in which one or
more of its directors, officers, or stockholders are directors, officers, or
stockholders, or have a financial interest shall be void or voidable solely for
this reason, or solely because the director or officer is present at or
participates in the meeting of the board or committee which authorizes the
contract or transaction, or solely because his, her, or their votes are counted
for such purpose, if: (I) the material facts as to his or her relationship or
interest and an to the contract or transaction are disclosed or are known to the
board of directors or the committee, and the board of directors or committee in
good faith authorizes the contract or transaction by the affirmative votes of a
majority of the disinterested directors, even though the disinterested directors
be less than a quorum; or (ii) the material facts as to his or her relationship
or interest and as to the contract or transaction are disclosed or are )known to
the stockholders entitled to vote thereon, and the contract or transaction is
specifically approved in good faith by vote of the stockholders or (iii) the
contract or transaction is fair an to the Corporation as of the time it is
authorized, approved, or satified by the board of directors, a committee
thereof, or the stockholders. Common or interested directors may be counted in
determining the presence of a quorm at a meeting of the board of directors or of
a Committee which authorizes the contract or transaction.

     TENTH. The corporation shall indemnify any person who was, is, or is
threatened to be made a party to a proceeding (as hereinafter defined) by
reason of the f act that he or she (I) is or wax a director or officer of the
corporation or (ii) while a director or officer of the Corporation, is or was
serving at the request of the Corporation as a director, officer, partner,
venturer, proprietor trustee, employee, agent, or similar functionary of another
foreign or domestic corporation, partnership joint ventures, sole
proprietorship, trust, employee benefit plan, or other enterprise, to the
fullest extent permitted under the Delaware General Corporation Law, as the same
exists or may hereafter be amended. such right shall be a contract right and as
such shall run to the benefit of any director or officer who is elected and
accepts the position of director or officer of the corporation or elect to
continue to serve an a director or officer of the Corporation while this Article
Tenth is in affect. Any repeal or amendment of this Article Tenth shall be
prospective only and shall not limit the rights of any such director or officer
or the obligations of the
<PAGE>

     Corporation with respect to any claim arising from or related to the
services of such director or officer in any of the foregoing capacities prior to
any such repeal or amendment to this Article Tenth. such right shall include the
right to be paid by the Corporation Kansas incurred in defending any such
proceeding in advance of its final


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the Corporation or its stockholders, (ii) for acts or omissions not in good
faith or which involve intentional misconduct or knowing violation of law, (iii)
under section 174 of the Delaware General Corporation Law, or (iv) for any
transaction from which the director derived an improper personal benefit. Any
repeal or amendment of this Article Eleventh by the


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<PAGE>

stockholders of the Corporation shall be prospective only, and shall not
adversely affect any limitation on the personal liability of a director of the
Corporation rising from an act or emission occurring prior to the title of such
repeal or amendment. In addition to the circumstances in which a director of the
corporation is not personally liable as met forth in the foregoing provisions of
this Article Eleventh, a director shall not be liable to the Corporation or its
stockholders to such further extent an permitted by any law hereafter enacted,
including without limitation any subsequent amendment to the Delaware General
Corporation Law.

     TWELFTH: The Corporation expressly elect not to be governed by Section 203
of the General Corporation Law of Delaware.

     I, the undersigned, for the purpose of forming the Corporation under the
laws of the State of Delaware, do make, file, and record this certificate of
incorporation and do certify that this is my act and dead and that the facts
stated herein are true and, accordingly, I do hereunto set my hand on this 11th 
day of December, 1990.


     Annette Beebe, Incorporator


                                        4
<PAGE>

      State of Delaware              PAGE 1
Office of the Secretary of State


     I, WILLIAM T. QUILLEN, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
MERGER, WHICH MERGES:

     "EXCELLENCE IN TRAINING CORPORATION", A IOWA CORPORATION,

     WITH AND INTO "PROFESSIONAL SECURITY TELEVISION NETWORK, INC." UNDER THE
NAME OF "EXCELLENCE IN TRAINING CORPORATION, A CORPORATION ORGANIZED AND
EXISTING UNDER THE LAWS OF THE STATE OF DELAWARE, AS RECEIVED AND FILED IN THIS
OFFICE THE THIRTY-FIRST DAY OF MARCH, A.D. 1994, AT:4:30 O'CLOCK P.M.

     A CERTIFIED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS FOR RECORDING.
<PAGE>

                                          William T. Quillen, Secretary of State

                              2249188 8100M       AUTHENTICATION:      7076648

                              944055212           DATE:               04-04-94
<PAGE>

          The Merger Agreement is on file at the principal place of business of
the surviving corporation at 11359 Aurora Avenue, Des Moines, Iowa 50322. Copies
of the Merger Agreement will be furnished by the surviving corporation, on
request and without cost, to any stockholder of any constituent corporation.

6.   The authorized shares of capital stock of each of the constituten
     corporations are as follows:

                           CONSTITUENT
                           CORPORATION       DESIGNATION               SHARES
AUTHORIZED

                           PSTN              Common Stock, l, 000
                                             $.01 par value

                           ETC               v
                           2,DW,DM

                                             Type A, no par value

                                             Voting Common Stock,
1,000,000
                                             Type B, no par value

                                             Voting Preferred Stock,
1,000,000       
                                             $l.00 par value per time

                                             Non-Voting No Cumulative 
                                             Convertible Preferred Stock, $1.00
                                             par value per share

                                             Callable Preferred Stock,

                                                                    1,000,000
                                             $1.00 par value per share


     IN WITNESS WHEREOF, the undersigned has executed this Certificate of Merger
as of the 1st day of March, 1994.

                                       PROFESSIONAL SECURITY TELEVISION
                                       NETWORK, INC.
<PAGE>

                                       By:

                                       Jack T. Smith, President
Attest:


Phyllis Farragut, Secretary


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