Seizure occurs where reasonable person would not feel free to leave.
In NY, there is a right to refuse answering questions, and running away does not provide probable cause for arrest.
Stop-and-Frisk not an arrest, but may be a seizure for 4th amendment.
for entry of dwelling to arrest, absent exigent circumstances or consent. If fails to knock and announce, arrest invalid.
Warrant not required
- crimes committed in presence of arresting party
- police officer reasonably believes one has committed a felony
- private person arrests AND felony has actually been committed and private person reasonably believes that the person being arrested is guilty.
Invalid arrest is NOT a defense to the crime charged. But evidence seized pursuant to an unlawful arrest may be SUPPRESSED.