Person of interest: a person who is believed to be possibly involved in a crime but has not been charged or arrested – www.merriam-webster.com
The above term has been used in law enforcement since 1937, according to Merriam-Webster. I don’t know what—or who—happened in 1937, but more recent examples of “person of interest” are Richard Jewell (innocent), Scott Peterson (not innocent), Andrew Cunanan (also not innocent), and James Caviezel (fictional).
Ramona DeFelice Long 