What are my rights?

What is the name of your state? Ohio. Two detectives came to my house in 1986 and asked me to go down to the Justice Center to give a hair and blood samples regarding a murder investigation. I did so willingly. I was held for a period of time in a room. When I asked to make a phone call.I was advised that as soon as the detectives who brought me in came back, I could. I was allowed eventually to use the phone. They took blood and hair samples, fingerprinted me, questioned me, and then advised me that I had to spend the night in order to stand in a line up the following day. I was released the next day after the line up because the "witness" could not identify me. I don't recall being read my rights and I was not charged, (so I thought).
Recently, I applied to drive a school bus and was denied the job because of what was found when they fingered printed me. They sent me the paperwork and on it it states that I was arrested for murder one and the charges were dismissed. There is no case number, court docket or anything. This black mark on my record is costing me good jobs. I am innocent and should not have to pay for something I did not do. I went to the Justice Center and no one could explain to me why it was on my record in the first place, there is no case number.
Please help. Have my civil liberties been bruised? Can I get this mark off my record without having to pay an attorney? Can I sue?