Did the Jews break their covenant with God when they crucified Jesus?

No one should be blamed for Jesus' crucifixion. Jesus knew exactly what he was doing and why. The crucifixion is misunderstood by most people - Jesus did this to demonstrate that it is possible to feel no anger and pain even in the worst of cirstances, and to show that bodily death is meaningless. Blame is a function of misperception, whereas love (including towards those others might view as enemies) is a becoming enlightened. Everyone will ultimately become enlightened and return to Heaven and happiness.