1) get the redhead and the cop to the other side, then bring back the cop.
2) then put the cop and a girl and cross, then bring back both the cop and the redhead
3) Put mom and a girl and cross, then bring back the mom
4) put the mom and dad and then cross, after that bring dad back, so that mom and two girls are now together on the other side
5) then take the read head and the cop to the other side, and bring back mom
6) Put both mom and dad and cross, then bring back dad
7) Put son and dad, then cross, then bring back cop and redhead
8) Put the cop and son in the boat and cross to the other side, then bring back the cop to the and take the redhead with him to the other side