Blood Innocents by Thomas H. Cook

Detective John Reardon can't believe this is the case he's been assigned.  Two fallow deer have been killed in the Central Park Zoo, and since they were donated by one of the wealthiest, most influential men in the city, it's a top priority case.  Although he doesn't agree, Reardon treats the case with the same doggedness and integrity he has given all his cases over his career.

The scene is similar to a butcher house.  One deer has been hacked to death by fifty-seven blows with something such as a hachet or axe.  The other deer was killed by one blow.  There is a two written in blood at the scene.  Why the savagery of one death and the relative ease of the other?  Was this targeted at the deer themselves or at the wealthy donor?  Who would be willing to kill with such a savage nature?

The stakes are soon raised.  A day later, two career women, roommates, are killed.  Their deaths seem to mimic that of the deer.  One woman is killed with one blow while her friend is hacked to death with fifty-seven blows.  This time the word Dos is written in blood.

Surely the two cases must be related.  As Reardon follows the trail of clues, the political pressure mounts.  The case must be solved quickly, and sure enough, soon a suspect is arrested.  There is evidence against him, and everyone is quick to congratulate themselves on a case solved.  But Reardon doesn't believe the suspect is guilty.  His investigation is leading to a different suspect, but can he fight the administration that is desperate to close the case?

This is Thomas H. Cook's first novel.  Mystery fans know him as one of the masters of the genre, and the features that make him a first-rate author are easily found in this early effort.  The plot twists and turns, and there are psychological issues that must be resolved.  This is a very satisfactory start to a stellar career.  This book is recommended for readers who enjoy mysteries and suspense.