While homicide is an issue, it is a much smaller problem (statistically speaking) than rape. I will be talking about forcible rape, as defined by the FBI.

In 2012 the FBI changed their definition of rape for UCR.

The old definition was “The carnal knowledge of a female forcibly and against her will.”

Many agencies interpreted this definition as excluding a long list of sex offenses that are criminal in most jurisdictions, such as offenses involving oral or anal penetration, penetration with objects, and rapes of males.

The new Summary definition of Rape is: “Penetration, no matter how slight, of the vagina or anus with any body part or object, or oral penetration by a sex organ of another person, without the consent of the victim.” (Text from a 2014 FAQ released by the FBI)

Numbers from 2012 onward reflect a different definition of what [forcible] rape is–legally speaking.


CIUS and Disaster Center both use the term “forcible rape” in their reporting. Both groups showed increases in total reported cases–though by hundreds in the case of CIUS and a thousand in the case of Disaster Center.

Rapes – National 2011-2013

year population total rate
CIUS 2011 311,587,816 84,175 27.00
CIUS 2012 313,914,040 84,376 26.90
CIUS 2013 316,128,839 79,770 25.20
Disaster Center 2011 311,587,816 84,175 27.00
Disaster Center 2012 313,873,685 85,141 27.10
Disaster Center 2013 316,128,839 79,770 25.20


CIUS local data only includes certain urban areas. Please note the population total for those rows.

MA – Estimates Based on National Averages

year population total rate
CIUS* 2011 4,578,146 1,236.10 27.00
CIUS* 2012 4,629,025 1,249.84 26.90
CIUS* 2013 4,679,143 1,263.37 25.20
Disaster Center 2011 6,607,003 1,783.89 27.00
Disaster Center 2012 6,645,303 1,794.23 27.10
Disaster Center 2013 6,692,824 1,807.06 25.20

*Includes Boston-Quincy, MA; Cambridge-Newton-Framingham, MA; and Peabody, MA and Rockingham County-Strafford County, NH

MA – Actual

year population total rate
CIUS* 2011 4,578,146 992 22.40
CIUS* 2012 4,679,143 1,286 22.40
CIUS* 2013 4,629,025 1,010 28.00
Disaster Center 2011 6,607,003 1,654 25.00
Disaster Center 2012 6,645,303 1,650 24.80
Disaster Center 2013 6,692,824 2,089 31.20

Since CIUS data is reported, there is incomplete reporting. The numbers above reflect 96.6%, 98.6%, and 95% of agencies reporting (respectively). The CIUS numbers and the DC ones are for different sized populations, with the regions of one being a subset of the other. There was a marked increase between 2012 and 2013 in the state of MA. Reporting for the newer, more liberal definition of rape was first recorded (fully) in 2013.

For city specific data, I also got numbers from City Data, which used a different term, so I included a column to specify. I could not think of a good way to organize this table. It would probably make a nicer graph.

Boston, Cambridge, Somerville – Actual

year population total rate term used
Boston – CRU 2010 N/A 256 N/A rape
Boston – City Data 2011 621,359 271 43.6 rape
Boston – CIUS 2011 621,359 271 43.6 forcible rape
Boston – City Data 2012 636,479 249 39.5 rape
Boston – CIUS 2012 630,648 112 17.6 forcible rape
Boston – CIUS 2013 N/A 138 N/A forcible rape
Cambridge – CRU 2010 N/A 16 N/A rape
Cambridge – City Data 2011 105,803 24 22.7 rape
Cambridge – CIUS 2011 105,803 24 22.7 forcible rape
Cambridge – City Data 2012 106,471 20 18.7 rape
Cambridge – CIUS 2012 106,981 10 9.3 forcible rape
Cambridge – CIUS 2013 N/A 8 N/A forcible rape
Somerville – CRU 2010 N/A 13 N/A rape
Somerville – City Data 2011 N/A 17 22.3 rape
Somerville – City Data 2012 77,104 23 29.8 rape


These are just forcible rapes (as defined above) reported to the police who then, in turn, report them to the FBI. Common practice says that this only scratches the surface of sexual assault as it exists around the nation.

I really need to figure out good ways to make graphs for these posts. I think some graphs would be nice.

If you’re still looking for a New Years resolution, I would recommend that you don’t rape anyone in 2015, and encourage people who have been raped to report it.


CIUS – National

CIUS – MA 2011, 2012, 2013

Disaster Center – National

Disaster Center – MA

City Data – BostonCity Data – Cambridge

City Data – Somerville

Uniform Crime Reporting


I know someone who doesn’t feel safe taking public transit or walking alone at night. I feel perfectly safe doing these things and, generally, prefer them over cabs and ubers. Maybe I lack the visceral fear some people develop as a result of being catcalled within the city. Maybe I grew up in a (more) dangerous place, and am left generally unfazed by suburban feel of Camberville. Regardless of the reason, I don’t worry about being spontaneously raped, mugged, or shot while out.

This is about homicide.

Homicide refers to the killing of a human–as manslaughter or murder. It also includes “justifiable killings.” The FBI only includes non-negligent killings and murder.


National rates are gathered from CIUS (Crime in the US, link below), which is maintained by the FBI, and the Disaster Center. The CIUS national numbers are from 2011 and 2012, the CIUS state numbers are from 2012 and 2013. Disaster Center numbers are from 2012 and 2013.

Homicide – National
Source Years Population per 100k total
CIUS 2011 311,587,816 4.7 14,661
CIUS 2012 313,914,040 4.7 14,827
Disaster Center 2012 313,873,685 4.7 14,752
Disaster Center 2013 316,128,839 4.5 14,196


For these numbers, I took the national rate per 100k (homicides per 100k people), and estimated based on the population [(population/100,000)*homicides per 100k] The CIUS number comes from only urban areas within MA. The Disaster Center numbers are from the entire state.

MA – Estimates Based on National Averages
Source Years Population per 100k total (estimated)
CIUS* 2012 1,183,933 4.7 55.64
CIUS* 2013 1,192,220 4.7 56.03
Disaster Center 2012 6,645,303 4.7 312.33
Disaster Center 2013 6,692,824 4.5 301.18
MA – Actual
Source Years Population per 100k total
CIUS* 2012 1,183,933 3.04** 36
CIUS* 2013 1,192,220 3.61** 43^
Disaster Center 2012 6,645,303 1.82** 121
Disaster Center 2013 6,692,824 2.05** 137

*Urban areas include Boston, Cambridge, Lowell, Springfield, and Worcester

**Maths done by me. For generating the per 100k, when the number was [(population/total homicides)*100,000].

^Four of these (9.3%) are related to the Boston Marathon Bombings.

We’re doing pretty well compared to the national average.

Local Numbers

These are about Boston, Cambridge, and Somverille. There are gaps. I left open the population totals (when they were not listed on the corresponding website) because I don’t know where they got their numbers from and, as you can see, their other numbers differ.

Boston, Cambridge, Somerville – Estimates assuming national rates
Source Years Population per 100k total
City Data – Boston 2011 N/A 4.7 N/A
City Data – Boston 2012 636,479 4.7 29.91
City Data – Cambridge 2011 N/A 4.7 N/A
City Data – Cambridge 2012 106,471 4.7 5.00
City Data – Somerville 2011 N/A 4.7 N/A
City Data – Somerville 2012 77,104 4.7 3.62
CIUS – Boston 2011 630,648 4.7 28.38
CIUS – Boston 2012  N/A 4.7 N/A
CIUS – Cambridge 2011 106,981 4.7 5.03
CIUS – Cambridge 2012 N/A 4.7 N/A
Boston, Cambridge, Somerville – Actual
Source Years Population per 100k total
City Data – Boston 2011 N/A 10.1 63
City Data – Boston 2012 636,479 9 57
City Data – Cambridge 2011 N/A 4.7 5
City Data – Cambridge 2012 106,471 0.9 1
City Data – Somerville 2011 N/A 0 0
City Data – Somerville 2012 77,104 0 0
CIUS – Boston 2011 630,648 3.65** 23
CIUS – Boston 2012 N/A N/A N/A
CIUS – Cambridge 2011 106,981 0.93** 1
CIUS – Cambridge 2012 N/A N/A N/A

**Maths done by me, see above.

Thoughts, Additional Table, Disclaimers, etc

City Data and CIUS have really radically different numbers. City Data does provide a disclaimer saying that their information may be neither accurate nor timely. They suggest using “at your own risk.” Comparing Disaster Center and CIUS is not really worthwhile, as they consider different populations.

It’s really sad that Boston’s crime rates are higher than Camberville’s.

The FBI’s Uniform Crime Reporting (UCR) has a program called National Incident-Based Reporting System (NIBRS) This is a very specific type of reporting system, which provides very different data than the above. Starting in 2011, data previously managed by UCR was replaced with NIBRS.

Homicides: NIBRS, UCR

Source Years Population Homicides
NIBRS 2013 316,128,839 3,465
UCR (National) 2010 308,745,538 14,748
UCR (MA) 2010 6,547,629 210
UCR (Boston) 2010 617,594 73
UCR (Cambridge) 2010 105,162 0
UCR (Somerville) 2010 75,754 0

In their pamphlet, NIBRS says that only 19% of homicides in 2013 were committed by a stranger. In terms of a random person killing me on the street, I’m not worried. In Camberville, over the past few years, there was only one stranger on stranger homicide and it was far beyond what one worries about when they think about being killed randomly.

Given infinite time and resources, it would be interesting to pull up each of the specific cases of homicide in Camberville (which is very doable).

I don’t know anything about statistics beyond folk knowledge and the things you learn in bio lab and from your statistician friends. That is to say: more than the average person on the average (i.e. non-Camberville) street, but not really a lot. My maths are based on what I know: public education and intuition. I am happy to receive criticism, advice, and corrections.

I know that there are lots of crimes other than homicides that are problems. Sexual assault is huge. Writing about homicide took me so long, I decided to shelve sexual assault until a possible future.


CIUS – National is maintained by the FBI. They use the term “murder and nonnegligent manslaughter.”


Disaster Center uses the term “murder.”

Disaster Center – National

Disaster Center – MA

City Data uses the term “murder.”

City Data – Boston

City Data – Cambridge

City Data – Somerville

Uniform Crime Reporting