The Bannerman Effect — John R. Maxim

A team of once-deadly government assassins led by Paul Bannerman has "retired" in the quiet, affluent town of Westport, Connecticut. All Bannerman and his people want is a normal life--but there are those who refuse to live and let live.
The Bannerman Effect
Former assassin Paul Bannerman knows that keeping a low profile is essential, but when he fell in love with the daughter of a legendary New York City cop, he broke his own unspoken rule. When Susan Lesko's life is threatened, the last of Bannerman's objectivity is shattered. Worst of all, his rage could blind Bannerman to an even graver threat that is operating in the shadows. The same covert government agency that disowned Bannerman and his people now plans to use them to test an experimental computer program designed to destroy criminal networks through strategically selected assassinations. The spooks have chosen Paul Bannerman and his operatives to be the guinea pigs in a potentially catastrophic experiment.