Perhaps this speaks to my ignorance, but Assassination seems incredibly common in the 19th and 20th century, killing even heads of state such as Lincoln, Ferdinand, and Ceaușescu with frequency, were as it seems almost absent in the 17th and 18th century. Presumably there have been people in all ages who had reason to assassinate state officials.
Just as a point of clarification, Ceaușescu was not assassinated by any definition of the term with which I am familiar. He was arrested, sentenced to death, and shot by firing squad during an ongoing overthrow of the government. It may have been a kangaroo court, but it far more closely resembled the overthrow and execution of Tsar Nicholas II or King Charles I than the assassination of Lincoln or Ferdinand.