I know this is a moot point, but this question could be easily answered in the US, unless these gunmen have access to several different weapons and change up. If bullets could have been recovered from the previous crimes (even in autopsy) and then they test fired the seized weapons, they could compare the bullet patterns and then could tell if these same weapons were used in previous crimes. I do not know if Jamaica has this level of forensic science yet. They could actually link these two to any previous incidents which would give the families some closure and bring some peace of mind to the community....however.... get two bad guys, 4 will usually replace them.