The Skogan (2006) article tests data on police contacts from which city?

Chicago.

Explanation:

The Skogan (2006) article tests the data of police-initiated and citizen-initiated contacts of police in Chicago. Wesley G. Skogan is a researcher in the fields of crime, policing, and so on.

He published a book in 2006 titled 'Police and Community in Chicago: A Tale of Three Cities.' The book is concerned about the crime studies and the policy of Community Policing developed by Chicago in the 1990s.

Community Policing is a policy or law enforcement that makes an officer operational in the same area and build relationship with the citizen so that they are able to reach them for help in time before crime occurs. So, the article basically concerns with the city of Chicago, and tests the data on police-initiated and citizen-initiated contacts of police.

Thus the correct answer is Chicago.

i would go with the last one

four sitting presidents have been assassinated while in office but the first was abraham lincoln,