On the city proper: 3 per day (1,101 murders per year). On the extended, metropolitan area and close urban centers, 11 murders per day (3,923). You should be aware however, that population of both regions is incredibly high: 8.77 million people for Mexico City proper and over 28.23 million for the extended region.
There were 13,144 murders throughout all of 2007.
Charles Sobhraj is alleged to have committed at least 12 murders.
None. Murders are committed by people, not by guns.
alot
Two
17,030
41
15,241
As there are many unsolved murders this cannot be known.
209
322
A lot