BOSTON (WHDH) - A 22-year-old man has been arrested in connection with the shooting death of a 12-year-old boy in Mattapan on Thursday, police announced. Boston<a class="excerpt-read-more" href="https://whdh.com/news/police-make-arrest-after-12-year-old-boy-killed-in-shooting-in-mattapan/">Read More</a>