Let say a person wss arrested by selling drugs on the street. Would it be legal to search the person's property (home computer, notes, mails, …) without a search warrant since the person was already arrested?
Google for "search incident to arrest". The police can search the suspect's immediate area, but cannot search a different location without a warrant.
I have also heard police will need a search warrant for a cell phone on the suspect. They can search pagers for incrimating numbers but a few judges have ruled the cell phones are analogous to computers and need search warrants. Not sure if that is always the case or not.
Just as an FYI, there has been some case law that allows for search of cell phones incident to arrest, but prior to completing the booking process.
In US v. Jacob Pierce Finley the ruling was that a cellphone is considered a "container" in which the police do not need a warrant to search as part of the arrest process.
Keep in mind I'm not a lawyer, so don't explicitly trust me on this. D