Apprentice in Death - J. D. Robb

Nature versus nurture...

The
shots came quickly, silently, and with deadly accuracy. Within seconds,
three people were dead at Central Park's ice skating rink. The victims:
a talented young skater, a doctor, and a teacher. As random as random
can be.

Eve Dallas has seen a lot of killers during her time with
the NYPSD, but never one like this. After reviewing security videos, it
becomes clear that the victims were killed by a sniper firing a
tactical laser rifle, who could have been miles away when the trigger
was pulled. And though the locations where the shooter could have set up
seem endless, the list of people with that particular skill set is
finite: police, military, professional killer.

Eve's husband,
Roarke, has unlimited resources - and genius - at his disposal. And when
his computer program leads Eve to the location of the sniper, she
learns a shocking fact: There were two-one older, one younger. Someone
is being trained by an expert in the science of killing, and they have
an agenda. Central Park was just a warm-up. And as another sniper attack
shakes the city to its core, Eve realizes that though we're all shaped
by the people around us, there are those who are just born evil...