<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: MARCH 31, 2003
                        DISTRIBUTION DATE: APRIL 21, 2003

                     CERTIFICATEHOLDER DISTRIBUTION SUMMARY

<TABLE>
<CAPTION>
                              Certificate    Certificate        Beginning
                                 Class       Pass-Through      Certificate         Interest         Principal
   Class          CUSIP       Description        Rate            Balance         Distribution     Distribution
-----------     ---------     -----------    ------------    ----------------    --------------   --------------
<S>             <C>           <C>            <C>             <C>                 <C>              <C>
     A          81744BAA4         SEN             1.73375%   1,064,445,319.86      1,537,901.73    10,199,985.91
    X-1         81744BAB2          IO             0.88498%               0.00        181,793.95             0.00
    X-2         81744BAC0          IO             1.39251%               0.00        968,667.49             0.00
    A-R         81744BAD8         SEN             3.42154%               0.00              0.00             0.00
    B-1         81744BAE6         SUB             2.13375%      16,815,000.00         29,899.17             0.00
    B-2         81744BAF3         SUB             3.01677%       8,968,000.00         22,545.34             0.00
    B-3         81744BAG1         SUB             3.01677%       6,165,000.00         15,498.66             0.00
    B-4         SMT0212B4         SUB             3.01677%       2,802,000.00          7,044.16             0.00
    B-5         SMT0212B5         SUB             3.01677%       1,681,000.00          4,225.99             0.00
    B-6         SMT0212B6         SUB             3.01677%       4,486,095.46         11,277.94             0.00
-----------     ---------     -----------    ------------    ----------------    --------------   --------------
Totals                                                       1,105,362,415.32      2,778,854.43    10,199,985.91
-----------     ---------     -----------    ------------    ----------------    --------------   --------------
</TABLE>

<TABLE>
<CAPTION>
                                                    Ending
                                 Current          Certificate         Total         Cumulative
   Class          CUSIP       Realized Loss         Balance        Distribution    Realized Loss
-----------     ---------     ---------------   ----------------   -------------   --------------
<S>             <C>           <C>               <C>                <C>             <C>
     A          81744BAA4                0.00   1,054,245,333.95   11,737,887.64             0.00
    X-1         81744BAB2                0.00               0.00      181,793.95             0.00
    X-2         81744BAC0                0.00               0.00      968,667.49             0.00
    A-R         81744BAD8                0.00               0.00            0.00             0.00
    B-1         81744BAE6                0.00      16,815,000.00       29,899.17             0.00
    B-2         81744BAF3                0.00       8,968,000.00       22,545.34             0.00
    B-3         81744BAG1                0.00       6,165,000.00       15,498.66             0.00
    B-4         SMT0212B4                0.00       2,802,000.00        7,044.16             0.00
    B-5         SMT0212B5                0.00       1,681,000.00        4,225.99             0.00
    B-6         SMT0212B6                0.00       4,486,095.46       11,277.94             0.00
-----------     ---------     ---------------   ----------------   -------------   --------------
Totals                                   0.00   1,095,162,429.41   12,978,840.34             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
   Class          Amount            Balance       Distribution   Distribution     Accretion     Loss (1)
----------   ----------------   ----------------  ------------   --------------   ----------    ----------
<S>          <C>                <C>               <C>            <C>              <C>           <C>
     A       1,080,076,000.00   1,064,445,319.86        694.88    10,199,291.03         0.00          0.00
    X-1                  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
    A-R                100.00               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
    B-2          8,968,000.00       8,968,000.00          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
    B-4          2,802,000.00       2,802,000.00          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
    B-6          4,486,095.46       4,486,095.46          0.00             0.00         0.00          0.00
----------   ----------------   ----------------  ------------   --------------   ----------    ----------
Totals       1,120,993,195.46                           694.88    10,199,291.03         0.00          0.00
----------   ----------------   ----------------  ------------   --------------   ----------    ----------
</TABLE>

<TABLE>
<CAPTION>
                Total             Ending              Ending
              Principal        Certificate         Certificate       Total Principal
   Class      Reduction          Balance            Percentage        Distribution
----------   -------------    ----------------     ---------------   ----------------
<S>          <C>              <C>                  <C>               <C>
     A       10,199,985.91    1,054,245,333.95          0.97608440      10,199,985.91
    X-1               0.00                0.00          0.00000000               0.00
    X-2               0.00                0.00          0.00000000               0.00
    A-R               0.00                0.00          0.00000000               0.00
    B-1               0.00       16,815,000.00          1.00000000               0.00
    B-2               0.00        8,968,000.00          1.00000000               0.00
    B-3               0.00        6,165,000.00          1.00000000               0.00
    B-4               0.00        2,802,000.00          1.00000000               0.00
    B-5               0.00        1,681,000.00          1.00000000               0.00
    B-6               0.00        4,486,095.46          1.00000000               0.00
----------   -------------    ----------------     ---------------   ----------------
Totals       10,199,985.91    1,095,162,429.41          0.97695725      10,199,985.91
----------   -------------    ----------------     ---------------   ----------------
</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                      Realized
   Class          Amount            Balance       Distribution    Distribution     Accretion      Loss (3)
----------   ----------------   ----------------  ------------    --------------   -----------    ----------
<S>          <C>                <C>               <C>             <C>              <C>            <C>
     A       1,080,076,000.00       985.52816641    0.00064336        9.44312347    0.00000000    0.00000000
    X-1                  0.00         0.00000000    0.00000000        0.00000000    0.00000000    0.00000000
    X-2                  0.00         0.00000000    0.00000000        0.00000000    0.00000000    0.00000000
    A-R                100.00         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
    B-2          8,968,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000
    B-3          6,165,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000
    B-4          2,802,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000
    B-5          1,681,000.00      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000
    B-6          4,486,095.46      1000.00000000    0.00000000        0.00000000    0.00000000    0.00000000
</TABLE>

<TABLE>
<CAPTION>
                                   Ending             Ending
             Total Principal     Certificate       Certificate       Total Principal
   Class        Reduction          Balance          Percentage        Distribution
----------   ----------------    -------------     ---------------   ----------------
<S>          <C>                 <C>               <C>               <C>
     A             9.44376684     976.08439957          0.97608440         9.44376684
    X-1            0.00000000       0.00000000          0.00000000         0.00000000
    X-2            0.00000000       0.00000000          0.00000000         0.00000000
    A-R            0.00000000       0.00000000          0.00000000         0.00000000
    B-1            0.00000000    1000.00000000          1.00000000         0.00000000
    B-2            0.00000000    1000.00000000          1.00000000         0.00000000
    B-3            0.00000000    1000.00000000          1.00000000         0.00000000
    B-4            0.00000000    1000.00000000          1.00000000         0.00000000
    B-5            0.00000000    1000.00000000          1.00000000         0.00000000
    B-6            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         1.73375%   1,064,445,319.86    1,537,901.73         0.00          0.00
   X-1                  0.00         0.88498%     246,506,384.56      181,793.95         0.00          0.00
   X-2                  0.00         1.39251%     834,753,935.31      968,667.49         0.00          0.00
   A-R                100.00         3.42154%               0.00            0.00         0.00          0.00
   B-1         16,815,000.00         2.13375%      16,815,000.00       29,899.17         0.00          0.00
   B-2          8,968,000.00         3.01677%       8,968,000.00       22,545.34         0.00          0.00
   B-3          6,165,000.00         3.01677%       6,165,000.00       15,498.66         0.00          0.00
   B-4          2,802,000.00         3.01677%       2,802,000.00        7,044.16         0.00          0.00
   B-5          1,681,000.00         3.01677%       1,681,000.00        4,225.99         0.00          0.00
   B-6          4,486,095.46         3.01677%       4,486,095.46       11,277.94         0.00          0.00
---------   ----------------    ------------   -----------------    ------------  -----------   -----------
 Totals     1,120,993,195.46                                        2,778,854.43         0.00          0.00
---------   ----------------    ------------   -----------------    ------------  -----------   -----------
</TABLE>

<TABLE>
<CAPTION>
            Non-Supported                                Remaining         Ending
              Interest                                    Unpaid        Certificate/
              Shortfall     Realized   Total Interest    Interest        Notational
  Class                     Loss (4)    Distribution     Shortfall         Balance
---------   -------------   ---------  ---------------   -----------   ----------------
<S>         <C>             <C>        <C>               <C>           <C>
    A              0.00          0.00     1,537,901.73          0.00   1,054,245,333.95
   X-1             0.00          0.00       181,793.95          0.00     246,064,901.67
   X-2             0.00          0.00       968,667.49          0.00     824,995,432.28
   A-R             0.00          0.00             0.00          0.00               0.00
   B-1             0.00          0.00        29,899.17          0.00      16,815,000.00
   B-2             0.00          0.00        22,545.34          0.00       8,968,000.00
   B-3             0.00          0.00        15,498.66          0.00       6,165,000.00
   B-4             0.00          0.00         7,044.16          0.00       2,802,000.00
   B-5             0.00          0.00         4,225.99          0.00       1,681,000.00
   B-6             0.00          0.00        11,277.94          0.00       4,486,095.46
---------   -------------   ---------  ---------------   -----------   ----------------
 Totals            0.00          0.00     2,778,854.43          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
             Original Face    Certificate    Certificate        Accrued        Interest      Interest
Class (5)       Amount           Rate      Notional Balance    Interest        Shortfall     Shortfall
---------   ----------------  -----------  ----------------    ------------   ------------   ----------
<S>         <C>               <C>          <C>                 <C>            <C>            <C>
    A       1,080,076,000.00    1.73375%      985.52816641       1.42388288     0.00000000   0.00000000
   X-1                  0.00    0.88498%      987.15350327       0.72800765     0.00000000   0.00000000
   X-2                  0.00    1.39251%      985.33632325       1.14340672     0.00000000   0.00000000
   A-R                100.00    3.42154%        0.00000000       0.00000000     0.00000000   0.00000000
   B-1         16,815,000.00    2.13375%     1000.00000000       1.77812489     0.00000000   0.00000000
   B-2          8,968,000.00    3.01677%     1000.00000000       2.51397636     0.00000000   0.00000000
   B-3          6,165,000.00    3.01677%     1000.00000000       2.51397567     0.00000000   0.00000000
   B-4          2,802,000.00    3.01677%     1000.00000000       2.51397573     0.00000000   0.00000000
   B-5          1,681,000.00    3.01677%     1000.00000000       2.51397383     0.00000000   0.00000000
   B-6          4,486,095.46    3.01677%     1000.00000000       2.51397682     0.00000000   0.00000000
</TABLE>

<TABLE>
<CAPTION>
                                                            Remaining
            Non-Supported                                    Unpaid
              Interest      Realized      Total Interest    Interest    Ending Certificate/
Class (5)     Shortfall     Loss (6)       Distribution     Shortfall   Notational Balance
---------   -------------   -----------   ---------------   ----------  -------------------
<S>         <C>             <C>           <C>               <C>         <C>
    A         0.00000000     0.00000000        1.42388288   0.00000000         976.08439957
   X-1        0.00000000     0.00000000        0.72800765   0.00000000         985.38555157
   X-2        0.00000000     0.00000000        1.14340672   0.00000000         973.81747070
   A-R        0.00000000     0.00000000        0.00000000   0.00000000           0.00000000
   B-1        0.00000000     0.00000000        1.77812489   0.00000000        1000.00000000
   B-2        0.00000000     0.00000000        2.51397636   0.00000000        1000.00000000
   B-3        0.00000000     0.00000000        2.51397567   0.00000000        1000.00000000
   B-4        0.00000000     0.00000000        2.51397573   0.00000000        1000.00000000
   B-5        0.00000000     0.00000000        2.51397383   0.00000000        1000.00000000
   B-6        0.00000000     0.00000000        2.51397682   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                        13,326,254.98
         Liquidations, Insurance Proceeds, Reserve Funds                    0.00
         Proceeds from Repurchased Loans                                    0.00
         Other Amounts (Servicer Advances)                                340.85
         Realized Losses                                                    0.00
         Prepayment Penalties                                               0.00
                                                                   -------------
Total Deposits                                                     13,326,595.83

Withdrawals
         Reimbursement for Servicer Advances                                0.00
         Payment of Service Fee                                       347,755.50
         Payment of Interest and Principal                         12,978,840.33
                                                                   -------------
Total Withdrawals (Pool Distribution Amount)                       13,326,595.83

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                                                   347,755.50
Supported Prepayment/Curtailment Interest Shortfall                         0.00
                                                                   -------------

Net Servicing Fee                                                     347,755.50
                                                                   =============
</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          116,869.21  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          116,869.21                 0              0.00                 0              0.00
</TABLE>

<TABLE>
<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       0.031949%     0.010671%    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%
              -----------------------               ----------------------              ----------------------
              0.031949%     0.010671%               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             0.00  0-29 Days      0                0.00
30 Days         0             0.00  30 Days        1          116,869.21
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          116,869.21
</TABLE>

<TABLE>
<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    0.031949%     0.010671%
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%              0.031949%     0.010671%
</TABLE>

Current Period Class A Insufficient Funds:                             0.00
Principal Balance of Contaminated Properties                           0.00
Periodic Advance                                                     340.85


<TABLE>
<CAPTION>
                     Original $     Original %       Current $       Current %
<S>                <C>              <C>            <C>               <C>
     Bankruptcy       218,860.00    0.01952376%       218,860.00     0.01998425%
          Fraud    33,629,796.00    3.00000001%    33,629,796.00     3.07075874%
 Special Hazard    11,209,932.00    1.00000000%    10,951,624.29     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                                          3.394300%
Weighted Average Net Coupon                                            3.016771%
Weighted Average Pass-Through Rate                                     3.016771%
Weighted Average Maturity (Stepdown Calculation)                            322

Beginning Scheduled Collateral Loan Count                                 3,152
Number of Loans Paid in Full                                                 22
Ending Scheduled Collateral Loan Count                                    3,130

Beginning Scheduled Collateral Balance                         1,105,362,415.32
Ending Scheduled Collateral Balance                            1,095,162,429.41
Ending Actual Collateral Balance at 31-Mar-2003                1,095,164,093.71

Monthly P&I Constant                                               3,127,304.79
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                     1,095,162,429.41

Scheduled Principal                                                      694.88
Unscheduled Principal                                             10,199,291.03
</TABLE>



                            MISCELLANEOUS REPORTING

<TABLE>
<S>                                                        <C>
      Principal Balance of 1-Month Libor Loans             251,602,105.84
      Principal Balance of 6-Month Libor Loans             843,560,323.57
      Pro Rata Senior Percentage                                96.298310%
      Senior Percentage                                        100.000000%
      Senior Prepayment Percentage                             100.000000%
      Subordinate Percentage                                     0.000000%
      Subordinate Prepayment Percentage                          0.000000%
</TABLE>