You should hire a criminal attorney asap. You probably don't know how badly hurt the person really is. Often injuries become worse days later. Get an attorney who can advise you of the best way to handle this.
It depends on what information you have. If you just have a person's name, but not their business, that's one thing. If you have their business name, they may not even have a business. There are many types of search engines today. As strange as it may sound, do a google search for the type of search engine you need. If you need to find a person, do a search for "people search engines," for instance. Same thing goes for anything. Then use the search engines that come up for what you need.