our dogs maliciously killed

on saturday, October 3rd 2009 right after our soccer games, my dad was out front working on the tractor tires when he came in and said the neighbor came by and said that he saw 2 dead dogs that looked like ours down by the road (1 was his, 1 was mine). i jumped in the truck with him and sure enough cam and sissy were lying dead on the side of the road 20 feet off of henrie road. he was airing up the tire on his tractor so he missed the whole thing. an emu was running around the neighborhood and they had chased it off, being herding dogs, they were just herding it. they were not in the road mind you, they were in the dirt and you you could see the tire tracks of someone that intentionally drove off of henrie road 100 feet from where they lie to hit them and then drove back onto it. they were killed immediately, you could even see where they rolled for a second when hit. this was all within a 5 minute window from the time my dad said they chased the emu off until the time that the neighbor came over to tell us that they were dead. we were all so upset, we raised cam from a puppy and have had sissy since before avery was born. you have never seen anything so sad as your little 6-year-old boy digging a hole with the backhoe, helping his grandpa put the dogs in it, and with tears streaming down his eyes in the wind, sit on the tractor and fill the hole back in. the kids cried, i cried, and my dad cried for these animals that we had grown attached to. i wanted to find the person who did this and show them what they had done. i can't believe how malicious some people can be. avery wanted them thrown in jail and it is hard to explain to a 6-year-old that in the eyes of the law the value of an animals life is not held as high as that of a humans, but to my little boy, there is no difference. he says that he saw a black van hit them, but it could have been a blazer or a tahoe or something too. he is quite sure that it had some sort of lights on the top of it. i just want somebody to take responsibility for this and to apologize to my kids. for the life of me, i can't think of one person that i know that would kill a dog so maliciously without a second thought to the consequences. any ideas?