Theres Rumford prepping the bomb in his office the night before he actually knew for sure that Haynes was going to turn his beloved Military Academy into a coed jr. College.
Then in a more humorous way, we see Columbo at the beginning of Make Me a Perfect Murder have his car accident. Well prior to the murder. "I think I hurt my neck...."
Im sure there are many others.
I always thought Grace Wheeler sneaking extra pills to knock out her husband was basically her murder plan already set in motion, even BEFORE she got the "no" answer from her husband on funding her show. Cold.