Is Caesar’s assassination as a justified means to freedom referenced to in the book that Plutarch wrote?

I do not feel that Plutarch draws a definite conclusion one way or the other as to whether the conspirators were justified in killing Caesar.
The assassination of Caesar is one of the pivotal points in history, partly because, 2,000 years later, there continues to be debate about its meaning and consequences for the western world. Plutarch seems to express the view that the conspirators were extremely naive, after having committed such an act, in believing in the purity of their own motives. He relates that after killing Caesar, they self-consciously marched in solidarity to the public forum to make a speech on the rightness of their actions, thinking the people of Rome would be sympathetic and grateful to them for eliminating a man they (the conspirators) considered a dangerous tyrant. But over the following days, public sentiment against them in Rome grew to the point where the conspirators realized they had to get out of town as fast as possible.
The outcome was, of course, that the freedom, in the name of which the conspirators said they had acted, was not restored to Rome. Instead, the Republic came to an end and an Empire was established after an extended period of war and civil disorder. Plutarch reports these events objectively, and basically lets the reader draw conclusions as to the ultimate significance of the death of Julius Caesar.