Yes for perjury or ig they are implicated with some new evidence. It's not double jeopardy if you were only a witness. Get immunity first if it's a concern.
"Probable Cause"
In some cases, yes. He can arrest on a misdemeanor arrest warrant. Officers are frequently obligated to make an arrest for domestic violence if they have probable cause to believe the domestic violence has occurred, even though they did not witness it. An officer can usually make an arrest in a traffic accident investigation, even though he did not witness the accident.
Yes, as long as they carry their warrant card. A citizen can arrest you if they witness you commit a crime. Police can do it if they suspect you have or are about to, whether they are on duty or not.
Rescue the individual being beaten and arrest the individuals assaulting them.
No. A police officer doesn't have to witness the assult to make the arrest. If the assault was of a Domestic Nature and the officers believe an assault occur he is required to make an arrest. The law 99-3-7 (3) uses the phrase "Shall" which gives the officer very little choice.
Please define what you mean by "turned in." If a witness observed the offense and turned your name over to the police, yes, of course, that information may be used to identify and arrest you.
an arrest warrant.
no, you can not. but police can arrest you.
The police can arrest you ANYWHERE.
You could try a citizen's arrest but the police man may refuse to be arrested. It is only a warranted police officer that is empowered by society to forcibly arrest someone.
Police officers can arrest you
No