<PAGE>
                                                                    Exhibit 31.2


CERTIFICATION OF THE CHIEF FINANCIAL OFFICER PURSUANT TO FORM OF RULE 13A-14(A),
AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002


I, Michael W. Taylor, certify that:


  1.   I have reviewed this quarterly report on Form 10-Q of America Service
       Group Inc.;

  2.   Based on my knowledge, this report does not contain any untrue statement
       of a material fact or omit to state a material fact necessary to make
       the statements made, in light of the circumstances under which such
       statements were made, not misleading with respect to the period covered
       by this report;

  3.   Based on my knowledge, the financial statements, and other financial
       information included in this report, fairly present in all material
       respects the financial condition, results of operations and cash flows
       of the registrant as of, and for, the periods presented in this report;

  4.   The registrant's other certifying officer and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Exchange Act Rules 13a-15(e) and 15d-15(e) for the registrant
       and have:

                  a) Designed such disclosure controls and procedures, or
                  caused such disclosure controls and procedures to be designed
                  under our supervision, to ensure that material information
                  relating to the registrant, including its consolidated
                  subsidiaries, is made known to us by others within those
                  entities, particularly during the period in which this report
                  is being prepared;

                  b) Evaluated the effectiveness of the registrant's disclosure
                  controls and procedures and presented in this report our
                  conclusions about the effectiveness of the disclosure
                  controls and procedures, as of the end of the period covered
                  by this report based on such evaluation; and

                  c) Disclosed in this report any changes in the registrant's
                  internal control over financial reporting that occurred
                  during the registrant's most recent fiscal quarter that has
                  materially affected, or is reasonably likely to materially
                  affect, the registrant's internal control over financial
                  reporting; and

  5.   The registrant's other certifying officer and I have disclosed, based on
       our most recent evaluation of internal control over financial reporting,
       to the registrant's auditors and the audit committee of the registrant's
       board of directors (or persons performing the equivalent functions):


        a) All significant deficiencies and material weaknesses in the design
        or operation of internal control over financial reporting which are
        reasonably likely to adversely affect the registrant's ability to
        record, process, summarize and report financial information; and


        b) Any fraud, whether or not material, that involves management or
        other employees who have a significant role in the registrant's
        internal control over financial reporting.


Dated:  November 14, 2003


                                     Name:    /s/ Michael W. Taylor
                                              ---------------------------------
                                     Title:   Senior Vice President &
                                              Chief Financial Officer