BROCKTON, Mass. — Police say two people were stabbed and one person was shot in a violent weekend in Brockton.Police say a 68-year-old man was taken to a Boston hospital after he was stabbed in the back during an attempted robbery at about 8 p.m. Saturday.His injuries were not considered life threatening.Police tell The Enterprise (http://bit.ly/169lcsD ) an 18-year-old man was shot just after 2 a.m.