When did the Pharisees stop being afraid to arrest Jesus?

In the beginning of Jesus's ministry, the Pharisees were angered at Jesus but were afraid of what the crowd thought if they were to arrest Jesus. "They looked for a way to arrest him, but they were afraid of the crowd because the people held that he was a prophet." Matthew 21:46. So, it makes me wonder how they mustered up the courage to arrest Jesus if he became more and more popular. How did they know that if they were to arrest Jesus, the crowd wouldn't turn against them after the display of the crowd just laying down palm trees when Jesus arrived in Jerusalem singing "Hosanna to the Son of David!"?