The state of Ohio has executed a Waterloo, Indiana man who fatally shot a security guard nearly 20 years ago.   Frederick Treesh was sentenced to die after he was convicted of the 1994 murder. Treesh was pronounced dead at 10:37 a.m. Wednesday.  Attorneys for Treesh had argued that their client had accepted responsibility for the killing but it was an unintentional consequence of a struggle for a gun.   Prosecutors maintained Treesh had intentionally murdered the man and tried to kill others, including police officers in pursuit.