Donna Leon is one of my favorite writers and especially as her Commissario Guido Brunetti Mysteries are set in Venice (my favorite city).
From the cover:
Summoned in the middle of the night to the hospital bed of a senior pediatrician, Commissario Brunetti is confronted with more questions than answers. Three men had burst into the doctor's apartment while the family was sleeping, attacked him, and taken away his eighteen-month-old boy.
As Brunetti delves into the case, he begins to uncover a story of infertility, desperation and illegal dealings.
The Italian police system can be a little confusing to those of us who don't live there and as shown in Suffer the Little Children the Polizia and Carabinieri don't always cooperate with each other although they often have the same jurisdictions.
Carabinieri (Arma dei Carabinieri) - Named after the traditional rifle they carried are part of the Italian armed forces (all Italian males aged 18-26 were once required to serve a 10-month period in the armed forces, but the draft was abolished in 2003). They are a special branch of the army and deal with national and serious crime, they are housed in barracks in all major towns. Note: according to an Italian tour guide, the idea of conscription was also supposed to bridge the conflict between Southern and Northern Italy as draftees were sent to other regions in the hope of unity between the two.
State Police (Polizia di Stato) - Investigative and law enforcement duties and provides security of roads, rail systems and airports.
Local police - Are responsible for traffic control and municipal administration.
And don't try to outrun their Highway Patrol officers as many are now driving Lamborghinis!