Unfortunately Scannerman5555 & Redhelmit13 are correct, since the alarm & security company purges in the 90's a lot has changed communications wise. However there are still a ton of companies still using their original VHF & UHF communications systems for whatever reason. There are hundreds of alarm monitoring & security companies still operating, way too many to post here, however I put together a small list of companies that I could find that may interest you. happy scanning.
IBI Security
Woodside, NY
WNCR949
460.9 MHz
463.925 MHz
Honeywell International
Melville, NY
WPQF301
464.95 MHz
Cambridge Security
NY, NY
WPMI597
457.625 MHz
WPXE415
457.2875 MHz
467.9125 MHz
APB Security & Alarm Monitoring Systems
Richmond NY
WPJN555
465.9375 MHz
USA Central Station Alarm Corp.
Port Chester, NY
WQFY309
465.9375 MHz
Prestige Protection Security
NY, NY
WPMH373
452.525 MHz
At Risk Protection & Investigations
NY, NY
WQFQ517
464.5 MHz
464.55 MHz
468.4625 MHz
469.0375 MHz
469.0625 MHz
Bell Security
NY, NY
WNXJ204
463.425 MHz
WPWD442
467.3125 MHz
Elite Investigations
Ny, NY
WQIY586
451.6375 MHz
451.7125 MHz
452.6875 MHz
456.4625 MHz
457.4875 MHz
FJC Security Corp.
Floral Park, NY
WQAA340
451.3625 MHz
451.775 MHz
452.0125 MHz
452.1125 MHz
461.025 MHz
461.2 MHz
WQAA360
452.6875 MHz
461.525 MHz
WQEQ646
451.95 MHz
461.4625 MHz
461.6875 MHz
461.7875 MHz
461.9625 MHz
463.2875 MHz
463.3375 MHz
463.975 MHz
464.325 MHz
GSS Security Service
NY,NY
WPQF523
451.7 MHz
461.225 MHz
464.175 MHz
Lance Investigation Service
Bronx, NY
KNFC567
464.1 MHz
Reliant Security Co.
Ny, NY
WNSQ477
463.925 MHz
Securicor International
NY, NY
WQCB928
451.875 MHz
Security & Intelligence Service
NY, NY
WPXA438
463.55 MHz
463.75 MHz
Spartan Security
NY, NY
WQFU759
463.6125 MHz
464.0625 MHz
464.1125 MHz
464.2375 MHz
Access Northern Security Alarm Monitoring Inc.
Bayside, NY
WPQI205
452.675 MHz
Adelis International Security
Rosedale, NY
WQBF453
466.625 MHz
469.8 MHz
Allied Security LLC
Syosset, NY
WQDX866
457.0625 NHz
WQFY240
451.1875 MHz
456.2875 MHz
461.0375 MHz
Suburban Security & Investigations
Smithtown, NY
WNPD616
461.8 MHz
Gold Shield Associates
Richmond, NY
WQAG593
461.775 MHz
462.025 MHz
466.125 MHz
City Heat Security
Oceanside, NY
WPDK526
464.4125 MHz
Gateway Security
Jamaica, NY
WPUR278
464.6375 MHz
Global Consulting Group
Jamaica, NY
WQIG604
464.4625 MHz
Landsdell Protective Agency
Jamaica, NY
KA64149
463.525 MHz
Motivated Security Services
Rego Park, NY
WQCI546
461.6375 MHz
463.4125 MHz
Summit Security
Jamaica, NY
WQFF538
460.6875 MHz
460.8375 MHz
Sebco Security
NY, NY
WQF363
464.475
Arista Security Central
Brooklyn, NY
WNDG990
461.5 MHz
Protection Plus Security Consultants
Brooklyn, NY
WPYS355
456.2875 MHz
464.5375 MHz
Sunset Park Security
Brooklyn, NY
WQEM761
451.775 MHz
Tight Security Group
Brooklyn, NY
WQHB330
461.9375 Mhz
4633.2125 MHz
FLRAILMAN