Apparently a bunch of break-ins have been happening on Jamaica Street lately; you can see some of them in the crime report widget on the neighborhood page here.

If you see someone acting unnaturally or in a suspicious manner, call 911, or Boston Police directly at 617-343-4911 (note that Enhanced 911 services won't work if you dial the 617 number, so don't use it if you're in need of help and don't know where you are.)  If you see someone breaking into a home, yell and scream for help while dialing 911.  If you hear someone yelling for help, grab your phone and a flashlight and get outside and find them.  This is the system they used in the Stony Brook neighborhood to combat muggings (only they used whistles.)  It sounds dorky, but it works.  Boston Police have done this for years....here's some more info: http://www.emeraldnecklacebudo.com/crime.htm

E-13 offers free safety evaluations of your home/apartment, and as mentioned, free whistles.  Call the local station-house: http://www.cityofboston.gov/police/districts/e13.asp

Remind your neighbors to always latch windows (even if you're not on the first floor - at one point, thieves were cleaning out apartments in JP by climbing up to the second floor!), always lock doors and cars, and not leave any sign of GPS units, phones, or music players in cars.  Make sure to secure bicycles, too - even if they're under your porch, it only takes a minute for it to disappear!  Ferris Wheels or Bikes Not Bombs will happily show you how to completely secure your bike no matter where you park it.

One last item: please help with reporting issues like broken streetlights, graffiti, un-shoveled sidewalks (which are the property owner's responsibility), "spot savers" (which are now illegal), trash left out improperly (placed out too early or not in containers, both of which attract rodents), and so on.  I've noticed that the area next to the Boston Public Housing complex is rife with trash, and it took three reports before the city did anything about it this summer.  You can anonymously report these issues quickly with your Android or iOS cell phone: http://www.cityofboston.gov/doit/apps/citizensconnect.asp