<PAGE>
                                                                    EXHIBIT 10.1

CONTACT: CUSTOMER SERVICES -- CTSLINK
         WELLS FARGO BANK MINNESOTA, N.A.
         SECURITIES ADMINISTRATION SERVICES
         7485 NEW HORIZON WAY
         FREDERICK, MD  21703
         WWW.CTSLINK.COM
         TELEPHONE:        (301) 815-6600
         FAX:              (301) 315-6660

                               SMT SERIES 2002-12
                          RECORD DATE: AUGUST 29, 2003
                      DISTRIBUTION DATE: SEPTEMBER 22, 2003

                     CERTIFICATEHOLDER DISTRIBUTION SUMMARY

<Table>
<Caption>

                      Certificate   Certificate          Beginning                                       Current
                         Class     Pass-Through         Certificate        Interest       Principal      Realized
 Class      CUSIP     Description      Rate               Balance        Distribution    Distribution      Loss
-------   ---------   -----------  ------------       ----------------   --------------  -------------   ---------

<S>       <C>         <C>          <C>                <C>                <C>             <C>             <C>
     A    81744BAA4   SEN               1.56000%      1,007,163,875.27     1,309,313.03  17,725,516.85        0.00
    X-1   81744BAB2   IO                0.80442%                  0.00       160,685.93           0.00        0.00
    X-2   81744BAC0   IO                1.15245%                  0.00       753,195.84           0.00        0.00
    A-R   81744BAD8   SEN               3.16542%                  0.00             0.00           0.00        0.00
    B-1   81744BAE6   SUB               1.96000%         16,815,000.00        27,464.50           0.00        0.00
    B-2   81744BAF3   SUB               2.63755%          8,968,000.00        19,711.26           0.00        0.00
    B-3   81744BAG1   SUB               2.63755%          6,165,000.00        13,550.39           0.00        0.00
    B-4   SMT0212B4   SUB               2.63755%          2,802,000.00         6,158.67           0.00        0.00
    B-5   SMT0212B5   SUB               2.63755%          1,681,000.00         3,694.76           0.00        0.00
    B-6   SMT0212B6   SUB               2.63755%          4,486,095.46         9,860.24           0.00        0.00
                                   ------------    -------------------   --------------  -------------   ---------
Totals                                                1,048,080,970.73     2,303,634.62  17,725,516.85        0.00
                                   ------------    -------------------   --------------  -------------   ---------


<Caption>

               Ending
            Certificate         Total         Cumulative
 Class         Balance       Distribution    Realized Loss
-------   ----------------   -------------   --------------

<S>       <C>                <C>             <C>
     A      989,438,358.42   19,034,829.88             0.00
    X-1               0.00      160,685.93             0.00
    X-2               0.00      753,195.84             0.00
    A-R               0.00            0.00             0.00
    B-1      16,815,000.00       27,464.50             0.00
    B-2       8,968,000.00       19,711.26             0.00
    B-3       6,165,000.00       13,550.39             0.00
    B-4       2,802,000.00        6,158.67             0.00
    B-5       1,681,000.00        3,694.76             0.00
    B-6       4,486,095.46        9,860.24             0.00
          ----------------   -------------   --------------
Totals    1,030,355,453.88   20,029,151.47             0.00
          ----------------   -------------   --------------

</Table>

All distributions required by the Pooling and Servicing Agreement have been
calculated by the Certificate Administrator on behalf of the Trustee.



<PAGE>



                        PRINCIPAL DISTRIBUTION STATEMENT

<Table>
<Caption>
                                   Beginning       Scheduled      Unscheduled
              Original Face       Certificate       Principal      Principal                    Realized     Total Principal
   Class          Amount            Balance       Distribution    Distribution     Accretion     Loss (1)       Reduction
---------    ----------------   ----------------  ------------   --------------    ---------    ----------   ---------------

<S>          <C>                <C>               <C>             <C>              <C>          <C>          <C>
     A       1,080,076,000.00   1,007,163,875.27          0.00    17,725,516.85         0.00          0.00     17,725,516.85
    X-1                  0.00               0.00          0.00             0.00         0.00          0.00              0.00
    X-2                  0.00               0.00          0.00             0.00         0.00          0.00              0.00
    A-R                100.00               0.00          0.00             0.00         0.00          0.00              0.00
    B-1         16,815,000.00      16,815,000.00          0.00             0.00         0.00          0.00              0.00
    B-2          8,968,000.00       8,968,000.00          0.00             0.00         0.00          0.00              0.00
    B-3          6,165,000.00       6,165,000.00          0.00             0.00         0.00          0.00              0.00
    B-4          2,802,000.00       2,802,000.00          0.00             0.00         0.00          0.00              0.00
    B-5          1,681,000.00       1,681,000.00          0.00             0.00         0.00          0.00              0.00
    B-6          4,486,095.46       4,486,095.46          0.00             0.00         0.00          0.00              0.00
             ----------------   ----------------  ------------   --------------    ---------    ----------   ---------------
Totals       1,120,993,195.46   1,048,080,970.73          0.00    17,725,516.85         0.00          0.00     17,725,516.85
             ----------------   ----------------  ------------   --------------    ---------    ----------   ---------------

<Caption>
                 Ending              Ending              Total
               Certificate         Certificate          Principal
   Class         Balance            Percentage        Distribution
---------  -----------------      --------------      -------------

<S>        <C>                    <C>                 <C>
     A        989,438,358.42          0.91608216      17,725,516.85
    X-1                 0.00          0.00000000               0.00
    X-2                 0.00          0.00000000               0.00
    A-R                 0.00          0.00000000               0.00
    B-1        16,815,000.00          1.00000000               0.00
    B-2         8,968,000.00          1.00000000               0.00
    B-3         6,165,000.00          1.00000000               0.00
    B-4         2,802,000.00          1.00000000               0.00
    B-5         1,681,000.00          1.00000000               0.00
    B-6         4,486,095.46          1.00000000               0.00
           -----------------      --------------      -------------
Totals      1,030,355,453.88          0.91914515      17,725,516.85
           -----------------      --------------      -------------
</Table>


 (1) Amount does not include excess special hazard, bankruptcy, or fraud losses
unless otherwise disclosed. Please refer to the prospectus supplement for a full
description.

                    PRINCIPAL DISTRIBUTION FACTORS STATEMENT


<Table>
<Caption>
                                     Beginning     Scheduled        Unscheduled                                      Total
              Original Face         Certificate    Principal         Principal                    Realized         Principal
   Class          Amount              Balance     Distribution     Distribution     Accretion      Loss(3)         Reduction
----------   ----------------      -------------  ------------     -------------    ----------    ----------      ------------
<S>          <C>                   <C>            <C>              <C>              <C>           <C>             <C>
     A       1,080,076,000.00       932.49352385    0.00000000       16.41136073    0.00000000    0.00000000       16.41136073
    X-1                  0.00         0.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    X-2                  0.00         0.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    A-R                100.00         0.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    B-1         16,815,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    B-2          8,968,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    B-3          6,165,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    B-4          2,802,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    B-5          1,681,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000
    B-6          4,486,095.46      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000        0.00000000

<Caption>
               Ending               Ending              Total
             Certificate          Certificate          Principal
   Class       Balance             Percentage        Distribution
---------    -------------        ------------       ------------
<S>          <C>                   <C>               <C>
     A        916.08216313          0.91608216        16.41136073
    X-1         0.00000000          0.00000000         0.00000000
    X-2         0.00000000          0.00000000         0.00000000
    A-R         0.00000000          0.00000000         0.00000000
    B-1      1000.00000000          1.00000000         0.00000000
    B-2      1000.00000000          1.00000000         0.00000000
    B-3      1000.00000000          1.00000000         0.00000000
    B-4      1000.00000000          1.00000000         0.00000000
    B-5      1000.00000000          1.00000000         0.00000000
    B-6      1000.00000000          1.00000000         0.00000000
</Table>


 (3) Amount does not include excess special hazard, bankruptcy, or fraud losses
unless otherwise disclosed. Please refer to the prospectus supplement for a full
description.



<PAGE>



                         INTEREST DISTRIBUTION STATEMENT
<Table>
<Caption>

                                                       Beginning                           Payment of
                                    Current           Certificate/         Current           Unpaid             Current
              Original Face       Certificate           Notional           Accrued           Interest           Interest
  Class          Amount               Rate              Balance            Interest          Shortfall          Shortfall
----------   ----------------   ----------------    ----------------   ----------------   ----------------   ----------------

<S>          <C>                <C>                 <C>                <C>                <C>                 <C>
    A        1,080,076,000.00            1.56000%   1,007,163,875.27       1,309,313.04               0.00               0.00
   X-1                   0.00            0.80442%     239,705,205.53         160,685.93               0.00               0.00
   X-2                   0.00            1.15245%     784,273,669.74         753,195.84               0.00               0.00
   A-R                 100.00            3.16542%               0.00               0.00               0.00               0.00
   B-1          16,815,000.00            1.96000%      16,815,000.00          27,464.50               0.00               0.00
   B-2           8,968,000.00            2.63755%       8,968,000.00          19,711.26               0.00               0.00
   B-3           6,165,000.00            2.63755%       6,165,000.00          13,550.39               0.00               0.00
   B-4           2,802,000.00            2.63755%       2,802,000.00           6,158.67               0.00               0.00
   B-5           1,681,000.00            2.63755%       1,681,000.00           3,694.76               0.00               0.00
   B-6           4,486,095.46            2.63755%       4,486,095.46           9,860.24               0.00               0.00
             ----------------                                          ----------------   ----------------   ----------------
 Totals      1,120,993,195.46                                              2,303,634.63               0.00               0.00
             ----------------                                          ----------------   ----------------   ----------------

<Caption>

                   Non-                                                   Remaining         Ending
                Supported                                                  Unpaid         Certificate/
                 Interest           Realized        Total Interest        Interest        Notational
  Class          Shortfall           Loss(4)         Distribution         Shortfall         Balance
----------   ----------------   ----------------   ----------------   ----------------   ----------------

<S>          <C>                <C>                <C>                <C>                <C>
    A                    0.00               0.00       1,309,313.03               0.00     989,438,358.42
   X-1                   0.00               0.00         160,685.93               0.00     238,519,919.41
   X-2                   0.00               0.00         753,195.84               0.00     767,733,439.01
   A-R                   0.00               0.00               0.00               0.00               0.00
   B-1                   0.00               0.00          27,464.50               0.00      16,815,000.00
   B-2                   0.00               0.00          19,711.26               0.00       8,968,000.00
   B-3                   0.00               0.00          13,550.39               0.00       6,165,000.00
   B-4                   0.00               0.00           6,158.67               0.00       2,802,000.00
   B-5                   0.00               0.00           3,694.76               0.00       1,681,000.00
   B-6                   0.00               0.00           9,860.24               0.00       4,486,095.46
             ----------------   ----------------   ----------------   ----------------
 Totals                  0.00               0.00       2,303,634.62               0.00
             ----------------   ----------------   ----------------   ----------------
</Table>

 (4) Amount does not include excess special hazard, bankruptcy, or fraud losses
unless otherwise disclosed. Please refer to the prospectus supplement for a full
description.

                     INTEREST DISTRIBUTION FACTORS STATEMENT

<Table>
<Caption>

                                                    Beginning                              Payment of
                                 Current           Certificate          Current             Unpaid           Current
           Original Face       Certificate           Notional           Accrued            Interest          Interest
Class(5)       Amount             Rate                Balance           Interest           Shortfall         Shortfall
-------   ----------------   ----------------    ----------------   ----------------   ----------------   ----------------

<S>       <C>                <C>                 <C>                <C>                <C>                <C>
      A   1,080,076,000.00            1.56000%       932.49352385         1.21224158         0.00000000         0.00000000
     X-1              0.00            0.80442%       959.91766628         0.64347899         0.00000000         0.00000000
     X-2              0.00            1.15245%       925.74985451         0.88906585         0.00000000         0.00000000
     A-R            100.00            3.16542%         0.00000000         0.00000000         0.00000000         0.00000000
     B-1     16,815,000.00            1.96000%      1000.00000000         1.63333333         0.00000000         0.00000000
     B-2      8,968,000.00            2.63755%      1000.00000000         2.19795495         0.00000000         0.00000000
     B-3      6,165,000.00            2.63755%      1000.00000000         2.19795458         0.00000000         0.00000000
     B-4      2,802,000.00            2.63755%      1000.00000000         2.19795503         0.00000000         0.00000000
     B-5      1,681,000.00            2.63755%      1000.00000000         2.19795360         0.00000000         0.00000000
     B-6      4,486,095.46            2.63755%      1000.00000000         2.19795590         0.00000000         0.00000000

<Caption>

               Non-                                                  Remaining             Ending
            Supported                                Total            Unpaid            Certificate/
             Interest            Realized           Interest          Interest           Notational
Class(5)     Shortfall            Loss(6)         Distribution        Shortfall             Balance
-------   ----------------   ----------------   ----------------   ----------------   ----------------

<S>       <C>                <C>                <C>                <C>              <C>
      A         0.00000000         0.00000000         1.21224157         0.00000000       916.08216313
     X-1        0.00000000         0.00000000         0.64347899         0.00000000       955.17109816
     X-2        0.00000000         0.00000000         0.88906585         0.00000000       906.22590926
     A-R        0.00000000         0.00000000         0.00000000         0.00000000         0.00000000
     B-1        0.00000000         0.00000000         1.63333333         0.00000000      1000.00000000
     B-2        0.00000000         0.00000000         2.19795495         0.00000000      1000.00000000
     B-3        0.00000000         0.00000000         2.19795458         0.00000000      1000.00000000
     B-4        0.00000000         0.00000000         2.19795503         0.00000000      1000.00000000
     B-5        0.00000000         0.00000000         2.19795360         0.00000000      1000.00000000
     B-6        0.00000000         0.00000000         2.19795590         0.00000000      1000.00000000
</Table>


(5) Per $1 denomination

(6) Amount does not include excess special hazard, bankruptcy, or fraud losses
unless otherwise disclosed. Please refer to the prospectus supplement for a full
description.

<PAGE>


                       CERTIFICATEHOLDER ACCOUNT STATEMENT

                               CERTIFICATE ACCOUNT

<Table>

<S>                                                        <C>
Beginning Balance

Deposits
         Payments of Interest and Principal                20,358,641.52
         Liquidations, Insurance Proceeds, Reserve Funds            0.00
         Proceeds from Repurchased Loans                            0.00
         Other Amounts (Servicer Advances)                        364.13
         Realized Losses                                            0.00
         Prepayment Penalties                                       0.00
                                                           -------------
Total Deposits                                             20,359,005.65

Withdrawals
         Reimbursement for Servicer Advances                        0.00
         Payment of Service Fee                               329,854.19
         Payment of Interest and Principal                 20,029,151.46
                                                           -------------
Total Withdrawals (Pool Distribution Amount)               20,359,005.65

Ending Balance                                                      0.00
                                                           =============
</Table>


                    PREPAYMENT/CURTAILMENT INTEREST SHORTFALL

<Table>

<S>                                                            <C>
Total Prepayment/Curtailment Interest Shortfall                        0.00
Servicing Fee Support                                                  0.00
                                                               ------------

Non-Supported Prepayment Curtailment Interest Shortfall                0.02
                                                               ============

</Table>

                                 SERVICING FEES

<Table>

<S>                                                     <C>
Gross Servicing Fee                                     329,854.19
Supported Prepayment/Curtailment Interest Shortfall           0.00
                                                      ------------

Net Servicing Fee                                       329,854.19
                                                      ============
</Table>

<PAGE>



<Table>
<Caption>

                              Beginning      Current       Current         Ending
       Account Type            Balance      Withdrawals    Deposits       Balance
-------------------------   ------------   ------------   ------------   ------------
<S>                         <C>            <C>            <C>            <C>
       Reserve Fund            10,000.00           0.00           0.00      10,000.00

</Table>


             LOAN STATUS STRATIFICATION/CREDIT ENHANCEMENT STATEMENT

<Table>
<Caption>
                DELINQUENT                                BANKRUPTCY                                FORECLOSURE
--------------------------------------     ---------------------------------------     -----------------------------------------
                No. of       Principal                   No. of        Principal                       No. of        Principal
                Loans        Balance                     Loans          Balance                        Loans          Balance

<S>           <C>           <C>            <C>         <C>             <C>             <C>          <C>            <C>
0-29 Days              0          0.00     0-29 Days             0            0.00     0-29 Days             0              0.00
30 Days                1    151,981.58       30 Days             0            0.00       30 Days             0              0.00
60 Days                0          0.00       60 Days             0            0.00       60 Days             0              0.00
90 Days                0          0.00       90 Days             0            0.00       90 Days             0              0.00
120 Days               0          0.00      120 Days             0            0.00      120 Days             0              0.00
150 Days               0          0.00      150 Days             0            0.00      150 Days             0              0.00
180+ Days              0          0.00     180+ Days             0            0.00     180+ Days             0              0.00
             -----------   -----------                 -----------    ------------                 -----------    --------------
                       1    151,981.58                           0            0.00                           0              0.00

<Caption>

                No. of       Principal                   No. of        Principal                       No. of        Principal
                Loans        Balance                     Loans          Balance                        Loans          Balance

<S>           <C>           <C>            <C>         <C>             <C>             <C>          <C>            <C>

0-29 Days       0.000000%     0.000000%    0-29 Days      0.000000%       0.000000%    0-29 Days      0.000000%         0.000000%
30 Days         0.033818%     0.014750%      30 Days      0.000000%       0.000000%      30 Days      0.000000%         0.000000%
60 Days         0.000000%     0.000000%      60 Days      0.000000%       0.000000%      60 Days      0.000000%         0.000000%
90 Days         0.000000%     0.000000%      90 Days      0.000000%       0.000000%      90 Days      0.000000%         0.000000%
120 Days        0.000000%     0.000000%     120 Days      0.000000%       0.000000%     120 Days      0.000000%         0.000000%
150 Days        0.000000%     0.000000%     150 Days      0.000000%       0.000000%     150 Days      0.000000%         0.000000%
180+ Days       0.000000%     0.000000%    180+ Days      0.000000%       0.000000%    180+ Days      0.000000%         0.000000%
             -----------   -----------                 -----------    ------------                 -----------    --------------
                0.033818%     0.014750%                   0.000000%       0.000000%                   0.000000%         0.000000%

<Caption>

                              REO                                                TOTAL
        --------------------------------------------        ---------------------------------------------
                        No. of           Principal                            No. of           Principal
                         Loans            Balance                              Loans           Balance

        <S>             <C>            <C>                   <C>           <C>                 <C>
        0-29 Days                0              0.00         0-29 Days                0              0.00
          30 Days                0              0.00           30 Days                1        151,981.58
          60 Days                0              0.00           60 Days                0              0.00
          90 Days                0              0.00           90 Days                0              0.00
         120 Days                0              0.00          120 Days                0              0.00
         150 Days                0              0.00          150 Days                0              0.00
        180+ Days                0              0.00         180+ Days                0              0.00
                       -----------       -----------                       ------------       -----------
                                 0              0.00                                  1        151,981.58

<Caption>


                        No. of           Principal                          No. of                Principal
                         Loans            Balance                            Loans                Balance

        <S>             <C>            <C>                   <C>           <C>                 <C>

        0-29 Days         0.000000%         0.000000%        0-29 Days         0.000000%         0.000000%
          30 Days         0.000000%         0.000000%          30 Days         0.033818%         0.014750%
          60 Days         0.000000%         0.000000%          60 Days         0.000000%         0.000000%
          90 Days         0.000000%         0.000000%          90 Days         0.000000%         0.000000%
         120 Days         0.000000%         0.000000%         120 Days         0.000000%         0.000000%
         150 Days         0.000000%         0.000000%         150 Days         0.000000%         0.000000%
        180+ Days         0.000000%         0.000000%        180+ Days         0.000000%         0.000000%
                       -----------       -----------                       ------------       -----------
                          0.000000%         0.000000%                          0.033818%         0.014750%


</Table>

<Table>

<S>                                          <C>       <C>                                           <C>   <C>               <C>
Current Period Class A Insufficient Funds:   0.00      Principal Balance of Contaminated Properties  0.00  Periodic Advance  364.13

</Table>


<Table>
<Caption>

                              Original $         Original %          Current $           Current %

<S>                         <C>                  <C>               <C>                   <C>
              Bankruptcy       218,860.00        0.01952376%          218,860.00         0.02124121%
                   Fraud    33,629,796.00        3.00000001%       33,629,796.00         3.26390236%
          Special Hazard    11,209,932.00        1.00000000%       10,303,554.54         1.00000000%
</Table>

Limit of subordinate's exposure to certain types of losses



<PAGE>

                              COLLATERAL STATEMENT

<Table>
<Caption>

Collateral Description                                         Mixed ARM
<S>                                                    <C>
Weighted Average Gross Coupon                                  3.015212%
Weighted Average Net Coupon                                    2.637546%
Weighted Average Pass-Through Rate                             2.637546%
Weighted Average Maturity (Stepdown Calculation)                    317

Beginning Scheduled Collateral Loan Count                         3,000
Number of Loans Paid in Full                                         43
Ending Scheduled Collateral Loan Count                            2,957

Beginning Scheduled Collateral Balance                 1,048,080,970.73
Ending Scheduled Collateral Balance                    1,030,355,453.88
Ending Actual Collateral Balance at 29-Aug-2003        1,030,357,509.92

Monthly P&I Constant                                       2,633,488.79
Special Servicing Fee                                              0.00
Prepayment Penalties                                               0.00
Realization Loss Amount                                            0.00
Cumulative Realized Loss                                           0.00

Ending Scheduled Balance for Premium Loans             1,030,355,453.88

Scheduled Principal                                                0.00
Unscheduled Principal                                     17,725,516.85
</Table>

                             MISCELLANEOUS REPORTING

<Table>

<S>                                            <C>
Principal Balance of 1-Month Libor Loans       244,233,023.19
Principal Balance of 6-Month Libor Loans       786,122,430.69
Pro Rata Senior Percentage                          96.095999%
Senior Percentage                                  100.000000%
Senior Prepayment Percentage                       100.000000%
Subordinate Percentage                               0.000000%
Subordinate Prepayment Percentage                    0.000000%
Payment Received from Cap Provide                           0

</Table>