CALLS FOR SERVICE AND OFFICER-INITIATED ACTIVITY

This section analyzes recorded police activity and Calls for Service to understand community requests for public safety services and identify areas where police activity may not be aligned with Calls for Service.

We include data on all Calls for Service (events reported via 911 calls, non-emergency calls to the department, direct contact with officers, or 311 calls that were routed to the police for a response) as well as all other recorded police activity, including Officer-Initiated Activities (events that officers initiated based on their own observations or assignment, rather than in response to Calls for Service). We request data only for events involving police, and not those solely addressed by fire or emergency medical responders. This data comes from Computer Aided Dispatch (CAD) systems, a central recording platform used by dispatchers to record Calls for Service and by officers to record their self-initiated activity, such as vehicle and pedestrian stops. In most jurisdictions, events recorded in CAD systems are not linkable to incidents recorded in police datasets on stops or use of force.

Insights on the type and volume of Calls for Service initiated by community members help identify the scope of community needs and the extent to which police are being asked to perform activities that should or could be handled by non-police responders. Mismatches between Calls for Service and deployment can shed light on potential inefficiencies that may be contributing to inequitable policing. It is important to note that Officer-Initiated Activity may also be influenced by community requests for public safety services that are not captured in the Calls for Service data, such as public safety concerns communicated to officers in community forums or council meetings. Calls for Service data also do not capture public safety concerns that community members did not call 911 or seek police services to address, making them an incomplete measure of community members’ public safety priorities.

It is important to note that Officer-Initiated Activity may be influenced by community requests for public safety services that are not captured in the Calls for Service data, such as public safety concerns communicated to officers in community forums or council meetings. Calls for Service data also do not capture public safety concerns that community members did not call 911 or seek police services to address, making them an imperfect measure of community members’ public safety priorities.

CALLS FOR SERVICE AND OFFICER-INITIATED ACTIVITIES BY EVENT TYPE

Cambridge Police Department recorded 724,553 total events between January 1, 2019 – December 6, 2022, including both Officer-Initiated Activities and Calls for Service.

For more detail on how events were categorized, see the More Information drop down.

What does this show?

The pie chart above shows three categories of events: those involving Bodily Harm, Property Harm, or Threats; Other Officer-Initiated Activity; and Other Calls for Service. The percentages are based on the number of events police recorded in each category, rather than the amount of time officers spent on each event type.

“Bodily Harm, Property Harm and Threats” includes all events involving either Bodily Harm (such as assault, robbery, or kidnapping), Property Harm (such as theft, burglary, arson, or vandalism), or Threats (such as harassment, shots heard, or extortion), regardless of whether the event was Officer-Initiated or initiated by a Call for Service. “Bodily Harm” is meant to capture events involving Bodily Harm crimes where a police response is required. This is not meant to include events involving accidental injuries where emergency medical services are the necessary responder, such as auto accidents not involving any serious or violent crime.

“Other Calls for Service” includes any events that did not involve Bodily Harm, Property Harm, or Threats and that were reported via 911 calls, non-emergency calls to the department, direct contact with officers, or 311 calls that were routed to the police for response.

“Other Officer-Initiated Activity” includes any events that did not involve Bodily Harm, Property Harm, or Threats that officers initiated based on their own observations or assignment, rather than in response to Calls for Service. This includes officers being assigned to particular activities (such as a patrol or school resource assignment), any requests for assistance from other officers or from outside agencies, and other activities police typically have some discretion over (such as vehicle and pedestrian stops).

How did we calculate this?

This data comes from Computer Aided Dispatch (CAD) systems, a central recording platform for all Officer-Initiated Activity and responses to Calls for Service. CAD is used by dispatchers to record Calls for Service and by officers to record their self-initiated activity, such as vehicle and pedestrian stops.

First, we categorized all recorded events into one of the three categories: those involving Bodily Harm, Property Harm, or Threats Other Officer-Initiated Activity; or Other Calls for Service. We then determined the number of events officers recorded in each of these event types. Finally, we calculated the percentage of all events officers recorded in each category by dividing the number of events in each category by the total number of events in all three categories.

Event categories are based on the initial call reason (provided to the dispatcher) or activity description (provided by the officer). Visit the Data Notes tab for details on the exact call types included and how they were categorized.

Data required for this analysis:

CALLS FOR SERVICE

This figure is highlights the reasons for which community members are most often calling emergency services. Of the 724,553 events included in the previous figure, 464,469 were police responses to Calls for Service rather than Officer-Initiated Activities.

81% of recorded Calls for Service that officers responded to did not involve reports of Bodily Harm, Property Harm, or Threats. These include requests related to public assistance, nuisances, and medical/fire assistance.

“Public Assistance” and “Other” comprise a combined 49% of calls for service attended by CPD compared to 19% for calls related to “Bodily Harm,” “Property Harm,” and “Threats.” Those former calls may reflect benign or even positive interactions between CPD and the public, but are likely not the most effective use of police resources and could be better addressed via community centered response models. For more detail on how events were categorized, see the “More Information” drop down below.

Note: This chart identifies what proportion of police activity—including officer-initiated activity and responses to calls for service—involve threats of bodily harm, property harm, or threats to those which do not. This chart does not provide qualitative analysis of the calls in question, which could be benign or even positive for those involved; however, calls not directly involving threats of bodily harm likely reflect inefficient distributions of police resources or incidents better suited to alternative response models.  

What does this show?

This figure only includes Calls for Service (events that were requested via 911 calls, non-emergency calls to the department, direct contact with officers, or 311 calls that were routed to the police for response). It does not include any events categorized as Officer-Initiated Activity.

This figure is meant to highlight the reasons for which community members are most often calling emergency services. This can help evaluate how often a police response is necessary, and whether there are sufficient Calls for Service that may not require a police response to warrant considering the use of alternative response models.

How did we calculate this?

First, we excluded all events categorized as Officer-Initiated Activity. If the data provided by the police do not indicate which events were Officer-Initiated, we categorized event type descriptions involving warrants, alarms or non-dispatched calls as Officer-Initiated, and then grouped all other event types as Calls for Service. Non-dispatched calls include requests for assistance from other officers or outside law enforcement agencies, activities that appear to be officer assignments (such as “directed patrol” or “walking the beat”), and other activities police typically have some discretion over (such as “traffic stop,” “subject stop,” “area check,” or “follow up”).

Then we categorized the Calls for Service based on the caller’s complaint type and calculated the percentage of calls in each category.

Data required for this analysis:

POLICE INTERVENTIONS IN MENTAL HEALTH CRISES

Police recorded  17,601  events as involving individuals experiencing mental health crises.

The Cambridge Police Department has a Mental Health Co-Response Team whereby a licensed clinician responds to these types of calls alongside police officers. However, this team was implemented after the data in this assessment were recorded.

Officers and 911 dispatchers are often not equipped to recognize or assist people experiencing mental health crises, so the number of “mental health” events reported above may underestimate the number of calls that could be directed to CPD’s Co-Response Team. Relying on police to address incidents related to mental health issues can unnecessarily escalate a mental health emergency to an incident ending in incarceration, use of force or death.

What does this show?

This figure shows the number of times officers recorded being involved in or responding to reports of people who were perceived as experiencing mental health crises. This figure only represents incidents that police or dispatchers coded with labels that clearly indicate a mental health-related event. Therefore, these findings likely underestimate the full extent of police interventions in the types of health and social issues that are routinely handled by existing unarmed community-based response programs around the country. The events in this figure include both Officer-Initiated Activities and police responses to Calls for Service.

Community-based response models — such as CAHOOTS (Eugene, Oregon), STAR (Denver, Colorado), BHEARD (New York City), and Portland Street Response — have generated early evidence showing that unarmed crisis services can effectively divert people experiencing mental health emergencies away from arrest and hospitalization, decrease the repeated use of such crisis services in the future, and improve the health of people who need emergency mental health care.

How did we calculate this?

To calculate this, we counted the number of events – both Officer-Initiated Activities and Calls for Service – in which a recorded event reason included terms such as “mental health,” “emotionally disturbed,” “suicide,” or “behavioral health.” This figure may undercount the number of police interventions in behavioral health-related incidents, as we did not include incidents police or dispatchers coded with labels such as “citizen assist,” “welfare check,” or “disturbance.” Such labels sometimes do – and sometimes do not – indicate a mental health-related event.

Data required for this analysis:

OFFICER-INITIATED PUBLIC ORDER CONCERNS, NUISANCES, AND SUSPICIOUS BEHAVIOR

This analysis examines where in the jurisdiction officers recorded initiating enforcement activities involving “Public Order Concerns,” “Nuisances,” and “Suspicious Behavior.” 

These types of enforcement activities can contribute to burdensome policing, and generally reflect officer-initiated interventions into situations that may be better addressed by trained social workers or mental health professionals, such as events involving unhoused individuals, truancy, drug use, missing persons, suspicious persons, or noise complaints.

Note: While CPE cannot speak to the outcome of individual police encounters, CPD has provided additional context about their efforts to strengthen trust with the community and ensure that officer interactions are as positive as they can be. 

What does this show?

This figure shows where in the jurisdiction enforcement events recorded as involving “Public Order Concerns,” “Nuisances,” and “Suspicious Behavior” were most highly concentrated per capita. The events in this figure are Officer-Initiated Activities, and not police responses to Calls for Service. Census tracts shaded in the darkest colors had the highest concentrations of these events.

 

Areas shaded in the lightest or second-lightest colors represent census tracts with relatively low or average concentrations of these events, respectively. Areas shaded in the darker third, fourth and fifth colors have high enough concentrations that they are respectively considered low-level, moderate or high statistical outliers relative to other tracts in the jurisdiction. Not all jurisdictions will include tracts shaded in each of these five colors. For example, a city with no high outliers would not have tracts in the fifth (darkest) color; a city with no moderate outliers would not have tracts in the fourth color, and so on.

How did we calculate this?

We calculated the number of events involving Public Order Concerns, Nuisances, and Suspicious Behavior recorded per 1,000 residents in each census tract— small geographic areas of approximately 4,000 residents — as defined by the Census Bureau. We then sort these into five even, ordinal categories (“quintiles”). The 20% of census tracts with the fewest number of events are in the first quintile and the 20% of census tracts with the most events are in the last category, with the remaining 60% evenly divided across the three middle quintiles in order relative to their frequencies of events. Only Officer-Initiated Activities are included in this calculation.

Data required for this analysis:

DENSITY OF OFFICER-INITIATED ACTIVITIES RELATIVE TO CALLS FOR SERVICE

This figure shows where in the jurisdiction there might be a mismatch between direct community requests for police presence and deployment directed by the department. The census tracts shaded in the deepest colors have the highest ratios of Officer-Initiated Activities relative to Calls for Service. Areas with outsized proportions of Officer-Initiated Activities relative to Calls for Service may be overpoliced relative to what the community is requesting, which can contribute to unnecessary or biased enforcement.

What does this show?

This figure shows where in the jurisdiction there might be a mismatch between direct community requests for police presence and deployment directed by the department. Areas shaded in the lightest or second-lightest colors represent census tracts with relatively low or average ratios of Officer-Initiated Activities to Calls for Service, respectively. Areas shaded in the darker third, fourth and fifth colors have high enough ratios that they are considered respectively low-, moderate-, and high-level statistical outliers relative to other tracts in the jurisdiction. Not all jurisdictions will include tracts shaded in each of these five colors. For example, a city with no high outliers would not have tracts in the fifth (darkest) color; a city with no moderate outliers would not have tracts in the fourth color, and so on.

How did we calculate this?

First, we calculated the number of recorded events that were Officer-Initiated Activities and the number that were police responses to Calls for Service using the department’s indication of which events were Officer-Initiated. If the data provided by the police had an indicator of which events were Officer-Initiated, we used that. If the data do not explicitly indicate which events were Officer-Initiated, we categorized event type descriptions involving warrants, alarms, or non-dispatched calls as Officer-Initiated, and then grouped all other event types as Calls for Service. Non-dispatched calls include requests for assistance from other officers or outside law enforcement agencies, activities that appear to be officer assignments (such as “directed patrol” or “walking the beat”), and other activities police typically have some discretion over (such as “traffic stop,” “subject stop,” “area check,” or “follow up”).

Next, we calculate the number of Officer-Initiated Activities per 1,000 Calls for Service by dividing the number of Officer-Initiated Activities by the number of Calls for Service and multiplying by 1,000. We sort these into five categories of census tracts — small geographic areas of approximately 4,000 residents, as defined by the Census Bureau — so that the 20% of tracts with the lowest ratio of Officer-Initiated Activities to Calls for Service are in the first category, the 20% of tracts with the highest ratio are in the last category, and the remaining 60% are divided evenly across the middle three categories in order relative to their ratios. Finally, we map these census tracts, with darker colors indicating tracts with higher levels of Officer-Initiated Activity relative to the number of Calls for Service.

Data required for this analysis:

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