The detective accused the mayor of pushing another investigator while recently trying to serve a subpoena on a friend of Kilpatrick. The two counts of assaulting or obstructing a police officer are each punishable by up to two years in prison.

"In my almost 20 years, first as a prosecutor and now as an attorney general ... I cannot recall ever seeing let alone hearing of a situation where a police officer trying to serve a subpoena was assaulted," Attorney General Mike Cox said at a news conference.

Kilpatrick spent Thursday night in a one-man jail cell with no TV for violating his bond in a criminal perjury case that has dogged him for months. Then Wayne County Circuit Judge Thomas Jackson altered the ruling of the lower court judge who ordered the mayor to jail.

Jackson said District Judge Ronald Giles went too far by not attaching some kind of cash bond to his ruling.

In order to get out of jail, Kilpatrick must pay a $50,000 cash bond and wear an electronic tether. He won't be allowed to travel.