EXHIBIT 12.1 PROTECTION ONE, INC. COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES (IN THOUSANDS) PREDECESSOR PROTECTION ONE 52 weeks 52 weeks 52 weeks Year Year Year ended ended ended Ended Ended Ended December December December December December December 20, 1994 20, 1995 20, 1996 31, 1996 31, 1997 31, 1998 -------- -------- --------- -------- ---------- ---------- Earnings: Net income (loss).................. $ (1,764) $ (5,923) $ (4,860) $ (656) $ (42,728) $ (2,463) Adjustments Extraordinary gain............... -- -- -- -- -- (1,591) Consolidated provision for income taxes.................... (1,081) (3,630) (2,978) (310) 28,628 (4,791) Fixed charges less interest income................. 13,467 12,159 10,879 15 33,483 56,129 -------- -------- --------- -------- ---------- ---------- Earnings as adjusted (A)........... $ 10,622 $ 2,606 $ 3,041 $ (951) $ 19,383 $ 47,284 -------- -------- --------- -------- ---------- ---------- -------- -------- --------- -------- ---------- ---------- Fixed Charges: Interest on debt and capitalized leases............................ 13,467 12,159 10,879 15 33,483 55,990 Amortization of deferred financing costs................... -- -- -- -- -- 139 -------- -------- --------- -------- ---------- ---------- Fixed charges (B).................... $ 13,467 $ 12,159 $ 10,879 $ 15 $ 33,483 $56,129 -------- -------- --------- -------- ---------- ---------- -------- -------- --------- -------- ---------- ---------- Ratio of earnings to fixed charges(A) divided by (B).......... -- -- -- -- -- Deficiency of earnings to fixed charges...................... $ 2,845 $ 9,553 $ 7,838 $ 966 $ 14,100 8,845