Under common law and 26 U.S.C. 7607, arrests may be made without warrant upon probable cause of upon "reasonable grounds to believe that the person to be arrested has committed" a narcotics felony
The combination of the naming of petitioner Toy by informer Hom Way as his source of supply of narcotics, and the attempted flight of Toy when the federal agent identified himself as a federal narcotics agent, gave the agent probable cause justifying the immediate arrest of Toy
The actions of Toy, when he learned that the man at his door was a federal narcotics agent, were sufficient corroboration of the prior information to constitute probable cause for Toy's arrest
Corroboration of a confession requires only evidence that will tend to establish the trustworthiness of the confession, and does not require evidence sufficient to establish the corpus delicti independently of the confession