That's right, Mona!
*Does* ''96 pairs of convicted criminals'' mean 192(2*96) criminals?
I was recently in charge of a government-funded study looking into the impact *of* prison sentences on criminals. For our study, we found 96 pairs of convicted criminals. (note: when you refer to "prison sentences" in a general sense, you can omit "the": "...the impact (that) prison sentences...."
Please feel free to send me a message and I will continue to help you to practice English! Michael, from Texas