How I Monitor Police Comms During A Protest

A short write up on my setup for monitoring police communications during protests in the Boston area. Includes gear and frequencies I monitor.

How I Monitor Police Comms During A Protest

A few things before I dive into my setup. Almost* all of the frequencies I monitor are pulled from publicly available sources. Anybody can look them up and with the right equipment can monitor them as well. There's a lot of Boston area frequencies and my hope is that I can point people who want to monitor themselves in the right direction.

*The exceptions are some of the federal frequencies I've found because I haven't identified the agencies behind them and submitted them to RadioReference. With that being said the feds aren't in my normal scanning rotation for protests.

The tl;dr is that I figure out what agency (or agencies) is/are working the protest and then I listen to figure out what channels they're using. Then I do my best to focus on those channels. My setup is pretty specific to Boston but could be applied pretty much anywhere assuming no encryption.

My gear setup is probably a bit overkill for what I monitor protest wise but it works for me. If you're looking to monitor what I monitor you'll need a device capable of monitoring Motorola Type II SmartZone analog trunked systems. Almost everything else is analog which pretty much any device can monitor. The one exception is BAPERN Tactical which is digital.

You can also go to and input some information and it'll tell you what scanners will work for your area. An SDR will also work but be aware you might need multiple dongles depending on the frequency range.

Gear List

Home Gear

  • Uniden SDS200
  • Comtelco All-Band Low-Profile Mobile Antenna
  • ProScan for logging
  • Uniden Sentinel for programming

Mobile Gear

  • Uniden BCD396XT
  • COMPACTenna SCAN-III on my car
  • Stock antenna if not in the car

I rarely use the BCD396XT for monitoring protests but I'm including it here as I will sometimes use it to monitor specific frequencies that are outside of my "protest rotation" such as MBTA Transit Police.

I utilize the recording function of the SDS200 to log every transmission to an SD card which I can then copy to my computer and put on something like OneDrive for public consumption.


All frequencies and talkgroups show below can be found in spreadsheet format here:!AnC3zGnjJhHqjc9-d_9Tce3mfZdDbw?e=3gJtRk

For protests in Boston there are two sets of frequencies I start to monitor and then whittle down from there: Boston Police and a favorites list I named Boston Events.

Boston Police is pretty much just what's on RadioReference and three channels I pulled from the Massachusetts Interoperability Field Operations Guide but haven't verified as being active.

Boston Police Frequencies
Boston Police Frequencies

Boston Events is the more curated list based on frequencies and talkgroups I've heard being used during protests. In terms of agencies it includes Boston Police and the Massachusetts State Police* which isn't super surprising since this is Boston focused.

*There may be other agencies invovled but for large scale events like protests they are often coordinated through the Law Enforcement Command Center (LECC) and utilize BAPERN Area Wide 4 or one of the MSP SOPS Channels.

Boston Events is comprised of the systems Conventional InterOp, Trunked InterOp and MA Army National Guard.

Boston Events Systems
Boston Events Systems

The tl;dr is that Conventional are Boston Police and BAPERN frequencies, Trunked InterOps are talkgroups on the Mass State Police trunked system and MA Army National Guard are known National Guard frequencies.

Conventional InterOp contains the frequencies that I know Boston Police has used during protests. The main ones are BPD Citywide Events and BAPERN Area Wide 4 which, if activated/patched, allow BPD and other agencies to coordinate without interfering with normal dispatch operations. I've heard bike/motorcycle units be coordateed on BPD Special Operations and BPD Interagency Operations is a patch to BFD and BEMS.

On the BAPERN side of things Area Wide 3 should really be removed as it's just BOLOs and usually not protest related. Area Wide 4 can be used by any agency for "wide area" opereations and is historically patched into BPD Citywide while BAPERN Tactical is often used for surveillance and may or may not be protest related. It's in there because I've heard it used once during a protest.

Conventional InterOp Frequencies
Conventional InterOp Frequencies

For Trunked InterOp I created three "Departments" that each contain a set of talkgroups. The sites I am using are Boston and Metro Boston Simulcast, though I will likely remove the Boston site as I get better reception on Metro Boston Simulcast. However the majority of these talkgroups are available Statewide so any site can be used. See for more information.

Trunked InterOp Departments
Trunked InterOp Departments
Trunked InterOp Sites
Trunked InterOps Sites

First up is Local Public Safety Events. As far as I can tell this is an InterOp channel between the MSP and local agencies in the Greater Boston Area (Troop A/H Coverage). It is inlcuded just in case it is used. These are the Boston are talkgroups, however there are ones for other Troops. For example it was not heavily used the night of May 31st, 2020 but was used on June 2nd, 2020.

Local Public Safety Events Channels
Local Public Safety Events Channels

State Police - Statewide is where the majority of the Massachusetts State Police comms will occur during a protest assuming a channel is activated. Much like Boston Police these SOPS channels are not always used and recently dispatch has been used to convey information.

It should be noted that SOPS 1-8 are Statewide talkgroups so there could be comms on multiples ones at the same time. It may take some listening to figure out which one is being used for a protest. In addition there does not appear to be a set SOPS channel for a Troop though SOPS-1 has been used historically in Boston.

The Statewide Helicopters and Mobiles talkgroup is primarily used for communication between the various airports and the helicopters. When they are on station the Air Wing will often utilize the relevant SOPS or dispatch talkgroup.

State Police - Statewide Channels
State Police - Statewide Channels

Finally there is Mass Events. From my understanding these can be used by any agency as long as they clear it with MEMA/MSP. These are included just in case they are used.

Mass Events Channels
Mass Events Channels

All of these talkgroups could be included in a single "Department" however I have them split out so I can remove one of them from the scanning rotation if need be. Them being split out does not really increase the scanning speed very much.

The last system is MA Army National Guard. These are frequencies that have been identified by Scan New England as belonging to the MA Army National Guard. I personally have heard a radio check from the LECC on 139.9625 MHz, CTCSS 85.4 so I know at least one is an active frequency. However I have never heard any operations on these frequencies.

I am missing an entry here and will be adding it. It appears that there has been digital activity on 139.9625 MHz with a NAC of N854 as recently as April 21st, 2021. See for more information.

MA Army National Guard Channels
MA Army National Guard Channels

That wraps up the frequencies and talkgroups I monitor for Boston specific protests. I also have Cambridge Police and Troop A/H programmed into my scanner and will add them to my scanner rotation during a protest if necessary.


I utilize the program ProScan to both log hits on my scanner and also give me the ability to remotely control it if need be. I can also utilize ProScan to log recordings in near real time to disk which can be used in conjunction with something like OneDrive to make them available online. Finally I use it to send my scanner audio to an IceCast server I am running.

As seen in the example below ProScan by default aggreates hits into a single line but this can be turned off and each hit will be on a sepereate line. While this causes more clutter it does make it easier to sort through recordings after the fact. I only turn this on if I am specifically recording using ProScan.

ProScan Interface
ProScan Interface

ProScan is an extremely powerful program and well worth the money. Currently due to technical limitations I do not log recordings to disk/OneDrive but if the need arises I can use a more powerful machine to do this until I upgrade the server that ProScan is running on.

And that's all the technical bits! I've already written a post about remotely monitoring protests and over events using a scanner or scanner feeds. That can be found below.

Tips For Remotely Monitoring Live Events With A Scanner
Some tips for covering live events remotely using a scanner or scanner feed.

Spreadsheets of the configs I listed above along with the hpe files for importing can be found here:!AnC3zGnjJhHqjc9-d_9Tce3mfZdDbw?e=3gJtRk

As always if you have any questions or want help programming shoot me a DM on Twitter or email me at ethan AT farewell-ladmin DOT com or farewell_ladmin AT protonmail DOT com.