Watch for Boston Marathon Charity Scams

Tragedy tends to strike twice.

The first is usually unexpected and takes the harsher toll — this time, three deaths, including an 8-year-old, and more than 100 injuries, some of which required amputation.

But the second tragedy is entirely predictable and can be avoided. Slimy people always try to profit from human empathy for victims, and they take money away from us and the people who need it most. That’s why the Better Business Bureau is already warning about fake charities setting up shop in Boston.

They advise that you should dedicate a little time along with your money: Do some research to make sure the charity is not poorly organized or questionable. If it’s brand new, it may be one or both.

Make sure you have a clear understanding of when and how the money will be used to help victims. You can find spending reports and tax documents for established charities at Charity Navigator, CharityWatch and GuideStar.

If you’re donating online, pay attention to the links you’re clicking and make sure the Web address is exactly what it should be, because some scammers try to imitate the look of established charities.

As the BBB puts it, “Don’t assume that charity recommendations on Facebook, blogs or other social media have already been vetted.” Fake information gets circulated widely and quickly by well-intentioned but busy people.

And while taxes may be the last thing on your mind now, remember that not all donations are tax-deductible. The charity needs to be a qualified 501(c)(3), and donations made to help a specific individual or family can’t be deducted. You can see if a charity is eligible at this page of the IRS website.

Speaking of taxes, Uncle Sam is cutting Boston area taxpayers a break on filing. The IRS says people living in Suffolk County, plus “victims, their families, first responders, others impacted by this tragedy who live outside Suffolk County and taxpayers whose tax preparers were adversely affected,” have until July 15 to file. (If you make estimated payments throughout the year, however, note that they say interest still applies.)