<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: FEBRUARY 28, 2003
                        DISTRIBUTION DATE: MARCH 20, 2003

                     CERTIFICATEHOLDER DISTRIBUTION SUMMARY

<TABLE>
<CAPTION>
                              Certificate    Certificate        Beginning
                                 Class       Pass-Through      Certificate         Interest
   Class          CUSIP       Description        Rate            Balance         Distribution
   -----          -----       -----------        ----            -------         ------------
<S>             <C>           <C>            <C>             <C>                 <C>
     A          81744BAA4         SEN             1.79000%   1,071,195,813.83      1,597,867.08
    X-1         81744BAB2          IO             0.82831%               0.00        171,112.64
    X-2         81744BAC0          IO             1.36870%               0.00        958,218.08
    A-R         81744BAD8         SEN             3.42294%               0.00              0.00
    B-1         81744BAE6         SUB             2.19000%      16,815,000.00         30,687.37
    B-2         81744BAF3         SUB             3.04176%       8,968,000.00         22,732.05
    B-3         81744BAG1         SUB             3.04176%       6,165,000.00         15,627.02
    B-4         SMT0212B4         SUB             3.04176%       2,802,000.00          7,102.50
    B-5         SMT0212B5         SUB             3.04176%       1,681,000.00          4,260.99
    B-6         SMT0212B6         SUB             3.04176%       4,486,095.46         11,371.34
                                                             ----------------      ------------
Totals                                                       1,112,112,909.29      2,818,979.07
                                                             ----------------      ------------
</TABLE>

<TABLE>
<CAPTION>
                                                       Ending
                  Principal         Current          Certificate         Total         Cumulative
   Class        Distribution     Realized Loss         Balance        Distribution    Realized Loss
   -----        ------------        -------          -----------      ------------    -------------
<S>             <C>              <C>               <C>                <C>             <C>
     A            6,750,493.97              0.00   1,064,445,319.86    8,348,361.05             0.00
    X-1                   0.00              0.00               0.00      171,112.64             0.00
    X-2                   0.00              0.00               0.00      958,218.08             0.00
    A-R                   0.00              0.00               0.00            0.00             0.00
    B-1                   0.00              0.00      16,815,000.00       30,687.37             0.00
    B-2                   0.00              0.00       8,968,000.00       22,732.05             0.00
    B-3                   0.00              0.00       6,165,000.00       15,627.02             0.00
    B-4                   0.00              0.00       2,802,000.00        7,102.50             0.00
    B-5                   0.00              0.00       1,681,000.00        4,260.99             0.00
    B-6                   0.00              0.00       4,486,095.46       11,371.34             0.00
                  ------------              ----   ----------------    ------------             ----
Totals            6,750,493.97              0.00   1,105,362,415.32    9,569,473.04             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
   Class          Amount            Balance       Distribution   Distribution     Accretion
   -----          ------            -------       ------------   ------------     ---------
<S>          <C>                <C>               <C>            <C>              <C>
     A       1,080,076,000.00   1,071,195,813.83        503.36     6,749,990.61         0.00
    X-1                  0.00               0.00          0.00             0.00         0.00
    X-2                  0.00               0.00          0.00             0.00         0.00
    A-R                100.00               0.00          0.00             0.00         0.00
    B-1         16,815,000.00      16,815,000.00          0.00             0.00         0.00
    B-2          8,968,000.00       8,968,000.00          0.00             0.00         0.00
    B-3          6,165,000.00       6,165,000.00          0.00             0.00         0.00
    B-4          2,802,000.00       2,802,000.00          0.00             0.00         0.00
    B-5          1,681,000.00       1,681,000.00          0.00             0.00         0.00
    B-6          4,486,095.46       4,486,095.46          0.00             0.00         0.00
             ----------------   ----------------        ------     ------------         ----
Totals       1,120,993,195.46   1,112,112,909.29        503.36     6,749,990.61         0.00
             ----------------   ----------------        ------     ------------         ----
</TABLE>

<TABLE>
<CAPTION>
                              Total             Ending              Ending
             Realized       Principal        Certificate         Certificate       Total Principal
   Class     Loss (1)       Reduction          Balance            Percentage        Distribution
   -----     --------       ---------          -------            ----------        ------------
<S>          <C>            <C>             <C>                  <C>               <C>
     A             0.00     6,750,493.97    1,064,445,319.86          0.98552817       6,750,493.97
    X-1            0.00             0.00                0.00          0.00000000               0.00
    X-2            0.00             0.00                0.00          0.00000000               0.00
    A-R            0.00             0.00                0.00          0.00000000               0.00
    B-1            0.00             0.00       16,815,000.00          1.00000000               0.00
    B-2            0.00             0.00        8,968,000.00          1.00000000               0.00
    B-3            0.00             0.00        6,165,000.00          1.00000000               0.00
    B-4            0.00             0.00        2,802,000.00          1.00000000               0.00
    B-5            0.00             0.00        1,681,000.00          1.00000000               0.00
    B-6            0.00             0.00        4,486,095.46          1.00000000               0.00
                   ----     ------------    ----------------          ----------       ------------
Totals             0.00     6,750,493.97    1,105,362,415.32          0.98605631       6,750,493.97
                   ----     ------------    ----------------          ----------       ------------
</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
              Original Face       Certificate      Principal       Principal
   Class          Amount            Balance       Distribution    Distribution     Accretion
   -----          ------            -------       ------------    ------------     ---------
<S>          <C>                  <C>             <C>             <C>              <C>
     A       1,080,076,000.00       991.77818397    0.00046604        6.24955152    0.00000000
    X-1                  0.00         0.00000000    0.00000000        0.00000000    0.00000000
    X-2                  0.00         0.00000000    0.00000000        0.00000000    0.00000000
    A-R                100.00         0.00000000    0.00000000        0.00000000    0.00000000
    B-1         16,815,000.00      1000.00000000    0.00000000        0.00000000    0.00000000
    B-2          8,968,000.00      1000.00000000    0.00000000        0.00000000    0.00000000
    B-3          6,165,000.00      1000.00000000    0.00000000        0.00000000    0.00000000
    B-4          2,802,000.00      1000.00000000    0.00000000        0.00000000    0.00000000
    B-5          1,681,000.00      1000.00000000    0.00000000        0.00000000    0.00000000
    B-6          4,486,095.46      1000.00000000    0.00000000        0.00000000    0.00000000
</TABLE>

<TABLE>
<CAPTION>
                                               Ending             Ending
             Realized    Total Principal     Certificate       Certificate       Total Principal
   Class     Loss (3)       Reduction          Balance          Percentage        Distribution
   -----     --------       ---------          -------          ----------        ------------
<S>          <C>         <C>                 <C>               <C>               <C>
     A       0.00000000        6.25001756     985.52816641          0.98552817         6.25001756
    X-1      0.00000000        0.00000000       0.00000000          0.00000000         0.00000000
    X-2      0.00000000        0.00000000       0.00000000          0.00000000         0.00000000
    A-R      0.00000000        0.00000000       0.00000000          0.00000000         0.00000000
    B-1      0.00000000        0.00000000    1000.00000000          1.00000000         0.00000000
    B-2      0.00000000        0.00000000    1000.00000000          1.00000000         0.00000000
    B-3      0.00000000        0.00000000    1000.00000000          1.00000000         0.00000000
    B-4      0.00000000        0.00000000    1000.00000000          1.00000000         0.00000000
    B-5      0.00000000        0.00000000    1000.00000000          1.00000000         0.00000000
    B-6      0.00000000        0.00000000    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>
                                                                                  Payment of
                                  Current          Beginning         Current        Unpaid       Current
             Original Face      Certificate      Certificate/        Accrued       Interest      Interest
  Class         Amount             Rate        Notional Balance      Interest      Shortfall    Shortfall
  -----         ------             ----        ----------------      --------      ---------    ---------
<S>         <C>                 <C>            <C>                  <C>           <C>           <C>
    A       1,080,076,000.00         1.79000%   1,071,195,813.83    1,597,867.09         0.00          0.00
   X-1                  0.00         0.82831%     247,895,225.91      171,112.64         0.00          0.00
   X-2                  0.00         1.36870%     840,115,587.92      958,218.08         0.00          0.00
   A-R                100.00         3.42294%               0.00            0.00         0.00          0.00
   B-1         16,815,000.00         2.19000%      16,815,000.00       30,687.38         0.00          0.00
   B-2          8,968,000.00         3.04176%       8,968,000.00       22,732.05         0.00          0.00
   B-3          6,165,000.00         3.04176%       6,165,000.00       15,627.02         0.00          0.00
   B-4          2,802,000.00         3.04176%       2,802,000.00        7,102.50         0.00          0.00
   B-5          1,681,000.00         3.04176%       1,681,000.00        4,260.99         0.00          0.00
   B-6          4,486,095.46         3.04176%       4,486,095.46       11,371.34         0.00          0.00
            ----------------                                        ------------         ----          ----
 Totals     1,120,993,195.46                                        2,818,979.09         0.00          0.00
            ----------------                                        ------------         ----          ----
</TABLE>

<TABLE>
<CAPTION>
                                                        Remaining         Ending
            Non-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     1,597,867.08          0.00   1,064,445,319.86
   X-1             0.00        0.00       171,112.64          0.00     246,506,384.56
   X-2             0.00        0.00       958,218.08          0.00     834,753,935.30
   A-R             0.00        0.00             0.00          0.00               0.00
   B-1             0.00        0.00        30,687.37          0.00      16,815,000.00
   B-2             0.00        0.00        22,732.05          0.00       8,968,000.00
   B-3             0.00        0.00        15,627.02          0.00       6,165,000.00
   B-4             0.00        0.00         7,102.50          0.00       2,802,000.00
   B-5             0.00        0.00         4,260.99          0.00       1,681,000.00
   B-6             0.00        0.00        11,371.34          0.00       4,486,095.46
                   ----        ----     ------------          ----
 Totals            0.00        0.00     2,818,979.07          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>
                                                                              Payment of
                               Current        Beginning         Current         Unpaid        Current
  Class      Original Face    Certificate    Certificate        Accrued        Interest      Interest
   (5)          Amount           Rate      Notional Balance    Interest        Shortfall     Shortfall
   ---          ------           ----      ----------------    --------        ---------     ---------
<S>         <C>               <C>          <C>                 <C>            <C>            <C>
    A       1,080,076,000.00    1.79000%      991.77818397       1.47940246     0.00000000   0.00000000
   X-1                  0.00    0.82831%      992.71522373       0.68523354     0.00000000   0.00000000
   X-2                  0.00    1.36870%      991.66517161       1.13107233     0.00000000   0.00000000
   A-R                100.00    3.42294%        0.00000000       0.00000000     0.00000000   0.00000000
   B-1         16,815,000.00    2.19000%     1000.00000000       1.82500030     0.00000000   0.00000000
   B-2          8,968,000.00    3.04176%     1000.00000000       2.53479594     0.00000000   0.00000000
   B-3          6,165,000.00    3.04176%     1000.00000000       2.53479643     0.00000000   0.00000000
   B-4          2,802,000.00    3.04176%     1000.00000000       2.53479657     0.00000000   0.00000000
   B-5          1,681,000.00    3.04176%     1000.00000000       2.53479477     0.00000000   0.00000000
   B-6          4,486,095.46    3.04176%     1000.00000000       2.53479671     0.00000000   0.00000000
</TABLE>

<TABLE>
<CAPTION>
                                                            Remaining
            Non-Supported                                    Unpaid
  Class       Interest      Realized      Total Interest    Interest    Ending Certificate/
   (5)       Shortfall      Loss (6)       Distribution     Shortfall   Notational Balance
   ---       ---------      --------       ------------     ---------   ------------------
<S>         <C>             <C>           <C>               <C>         <C>
    A         0.00000000     0.00000000        1.47940245   0.00000000         985.52816641
   X-1        0.00000000     0.00000000        0.68523354   0.00000000         987.15350327
   X-2        0.00000000     0.00000000        1.13107233   0.00000000         985.33632324
   A-R        0.00000000     0.00000000        0.00000000   0.00000000           0.00000000
   B-1        0.00000000     0.00000000        1.82499970   0.00000000        1000.00000000
   B-2        0.00000000     0.00000000        2.53479594   0.00000000        1000.00000000
   B-3        0.00000000     0.00000000        2.53479643   0.00000000        1000.00000000
   B-4        0.00000000     0.00000000        2.53479657   0.00000000        1000.00000000
   B-5        0.00000000     0.00000000        2.53479477   0.00000000        1000.00000000
   B-6        0.00000000     0.00000000        2.53479671   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                         9,895,351.97
         Liquidations, Insurance Proceeds, Reserve Funds                    0.00
         Proceeds from Repurchased Loans                                    0.00
         Other Amounts (Servicer Advances)                             23,986.10
         Realized Losses                                                    0.00
         Prepayment Penalties                                               0.00
                                                                    ------------
Total Deposits                                                      9,919,338.07

Withdrawals

         Reimbursement for Servicer Advances                                0.00
         Payment of Service Fee                                       349,865.04
         Payment of Interest and Principal                          9,569,473.03
                                                                    ------------
Total Withdrawals (Pool Distribution Amount)                        9,919,338.07

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                     0.00
                                                                    ============
</TABLE>


                                    SERVICING FEES

<TABLE>
<S>                                                                 <C>
Gross Servicing Fee                                                   349,865.04
Supported Prepayment/Curtailment Interest Shortfall                         0.00
                                                                    ------------

Net Servicing Fee                                                     349,865.04
                                                                    ============
</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           23       8,873,176.57  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
                -----------------------               ---------------------               ---------------------
                  23       8,873,176.57                 0              0.00                 0              0.00
</TABLE>

<TABLE>
<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        23       8,873,176.57
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                 23       8,873,176.57
</TABLE>

<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       0.000000%     0.000000%    0-29 Days  0.000000%    0.000000%   0-29 Days  0.000000%    0.000000%
30 Days         0.729695%     0.802740%    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%
                -----------------------               ---------------------               ---------------------
                0.729695%     0.802740%               0.000000%    0.000000%              0.000000%    0.000000%
</TABLE>

<TABLE>
<CAPTION>
               REO                                 TOTAL
----------------------------------  ------------------------------------
             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    0.729695%     0.802740%
  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%              0.729695%     0.802740%
</TABLE>

Current Period Class A Insufficient Funds:                     0.00
Principal Balance of Contaminated Properties                   0.00
Periodic Advance                                          23,986.10


<TABLE>
<CAPTION>
                              Original $         Original %          Current $           Current %
<S>                         <C>                  <C>               <C>                   <C>
              Bankruptcy       218,860.00        0.01952376%          218,860.00         0.01979984%
                   Fraud    33,629,796.00        3.00000001%       33,629,796.00         3.04242261%
          Special Hazard    11,209,932.00        1.00000000%       11,053,624.15         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                                          3.419269%
Weighted Average Net Coupon                                            3.041755%
Weighted Average Pass-Through Rate                                     3.041755%
Weighted Average Maturity (Stepdown Calculation)                            323

Beginning Scheduled Collateral Loan Count                                 3,167
Number of Loans Paid in Full                                                 15
Ending Scheduled Collateral Loan Count                                    3,152

Beginning Scheduled Collateral Balance                         1,112,112,909.29
Ending Scheduled Collateral Balance                            1,105,362,415.32
Ending Actual Collateral Balance at 28-Feb-2003                1,105,361,700.42

Monthly P&I Constant                                               3,169,347.45
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                     1,105,362,415.32

Scheduled Principal                                                      503.36
Unscheduled Principal                                              6,749,990.61
</TABLE>


                             MISCELLANEOUS REPORTING

<TABLE>
<S>                                                      <C>
        Principal Balance of 1-Month Libor Loans         252,001,194.92
        Principal Balance of 6-Month Libor Loans         853,361,220.40
        Pro Rata Senior Percentage                            96.320779%
        Senior Percentage                                    100.000000%
        Senior Prepayment Percentage                         100.000000%
        Subordinate Percentage                                 0.000000%
        Subordinate Prepayment Percentage                      0.000000%
</TABLE>