At the helm of the NYPD from 1934-45 was Lewis Valentine (pictured), a stalwart of the force for more than 30 years who had a reputation for brutality . Today they are everyday heroes, New York's finest, but the New York Police Department has had a more chequered past than most would imagine. Bernard Whalen's new book 'The NYPD's First Fifty Years' is a tale of kickbacks, mob violence and secret KKK members. Whalen charts the early rise of the world renowned police department from it beginnings in 1898 when the New York area's 18 independent police forces merged into one. A variety of men led the force through its formative years, 21 in total. Some were forward looking, some were practical but more than a fair share were scoundrels, larcenists or at the very least guilty of dereliction of duty. The department's first chief of police, William Devery, who held the post from 1898-1901, was known as the king of kickbacks. A former bar tender, Devery had to give a backhander just to get into the force, and was never shy about trading dollars for ranks, the New York Post reported. Police officers of the time had to pay exorbitant fees, more than year's starting salary to become a captain, but for Devery the under the table payments could easily be recovered through other means. In his early career, when taking command of a lower East Side Police Precinct, Devery was recorded as saying that there was a great deal of 'grafting' going on among his subordinates and that he would put a stop to it so he could line his own pockets. On the back of bribes paid to him Devery was able to buy a baseball team, the New York Highlanders, a forerunner to the New York Yankees, which he eventually sold for $300,000 in 1915. Theodore Bingham who held Devery's former post from 1906 to 1909 had his own unique set of character traits and is described in 'The NYPD's First Fifty Years' as being pathologically blunt. A former Brigadier General, Bingham lost his leg in an Army engineering accident in Buffalo. He worked throughout his career to remove special civil service protections on police inspectors who he could not promote or demote. When he won his battle to fire the people he wanted he turned his attention to NYPD captains who had the same status. He was recorded as saying 'I wish that about 40 police captains would die overnight. They are no good.' Bingham's tendency for indiscretion landed him in hot water again when he let slip the whereabouts one of his top lieutenants who had become famous for tracking down the mob. The police chief decided to tell reporters that his star lieutenant was on a secret mission in Italy tracking down the criminal backgrounds of Mafioso, Black Hand members. The officer was later found, shot dead outside a Palermo café. Devery (left) was the king of kickbacks while Theodore Bingham (right) was 'pathologically blunt' Richard Entright who presided over the NYPD from 1918 to 1925 has become infamous for his decision not to root out Klu Klux Klan members in his own force. He was handed orders from the then mayor of New York to look into allegations that one of the city's Baptist ministers was allowing the white supremacist group to recruit from among his parishioners. The extent of KKK influence in the city was far greater than either Entright or Mayor John Francis Hylan knew and an astonishing 800 suspected Klansmen were found to be living in New York – 30 of them were police officers. Richard Entright (pictured) failed to even try and remove the KKK from within his own police force . Presented with the size of the problem and information that as far as it was known none of the individuals had broken the law, Entright decided to do nothing. Joseph Warren, chief of police for only one year from 1927 to 28 became famous for incompetence rather than any particularly nefarious acts. Upon the death of Arnold Rothstein, once New York's most notorious gangsters and the real-life inspiration for F. Scott Fitzgerald's character, Meyer Wolfsheim, in 'The Great Gatsby', warren told his top detective to take a holiday. Warren, who it has emerged may have suffered from mental problems, fumbled the open and shut case and, as Warren was pushed from his post, the key suspect walked free. At the helm of the NYPD from 1934-45 was Lewis Valentine, a stalwart of the force for more than 30 years. Valentine, whose autobiography was appropriately titled, 'Nightstick' and who would later host a radio show, 'Gang Busters,' was the embodiment of a tough cop. Under his tenure NYPD officers were encouraged to mercilessly beat their suspects and promotions were on offer to those who could – in Valentine's words 'throw the gorillas around'. Following the slow death of one officer who had been killed a week earlier Valentine ordered his men to shoot 'wise guys' on sight, telling them they shoulf 'draw quickly and shoot accurately'.
NYPD's secret history from first 50 years unveiled in book about the force .
Looking at men who led the police, book describes kickbacks and brutality .
One chief of police led the mob to the whereabouts of his star detective .
Another failed to investigate KKK infiltration in the ranks of his department .