Captain Daniel Patrick Mahoney, NYPD (ret.) spend 25 years with the New York City Police Department, 17 of them as a detective.  His assignments included the Career Criminal Apprehension Unit, Manhattan Robert Unit and the 109 Homicide Assault Task Force.

At the age of 17, he enlisted in the United States Marine Corps, serving as a machine gunner with the 9^th Marines in Vietnam.  After his discharge in 1968, he applied to the New York City Police Department.   Captain Daniel Patrick Mahoney is the author of Detective First Grade; Edge of the City; Hyde; Once in, Never Out; Black and White; The Two China Towns; The Protectors; and, Justice.

The Library Journal said of Once In, Never Out, “Detective Brian McKenna makes his fourth appearance in this fast-paced audiobook. He is asked to investigate the disappearance of a young Irish waitress, whose brother is the aide to the Cardinal of the Archdiocese of New York. He tracks the woman to Iceland, where she was horribly murdered by a former New York City detective, now an outlaw IRA bomber. McKenna then joins forces with a brilliant Icelandic detective investigating the bombing death of a British diplomat and his wife. The story moves to Ireland, with McKenna receiving an introduction to the troubles between Briton, Irish, Protestant, and Catholic, and climaxes with the final conflict back in New York on St. Patrick's Day. While not sparkling in plot or characterization, this tale is enjoyable, and reader Adams Morgan does an excellent job presenting it.”

According to one reader of Once In, Never Out, “This book grabs your attention and doesn't let go for a week after you finish it. As a former Police Officer and someone who has been to Iceland and Northern Ireland I found this book to be very realistic in every sense. Brian McKenna is the type of guy you want to be your partner, your friend , and the cop who comes when you dial 911. He is Dan Mahoney's main character in all of his books, a NYPD Detective who in spite of past problems rises to the task of solving the toughest cases that come along. In this book he travels to Iceland to find a missing girl and ends up in a personal battle with the IRA's best bomb man. If you want a safe, predictable story then DO NOT buy this book. But if you want a gripping, realistic story of intrigue, with heart stopping action thrown in. Then get off your chair and go buy this book !”

Publisher’s Weekly said of Hyde, “The overall mood of this police procedural about a serial killer of homeless AIDS sufferers in New York is, astonishingly, upbeat and energetic, even chipper-as befits Mahoney's vision of New York as the kind of city where assistant commissioner of the NYPD Brian McKenna (last seen in Edge of the City) can quit his job, take a salary cut and rejoin the ranks as a detective in the 17th Precinct, all because he loves the work. Here, McKenna is assigned to investigate the demise of a homeless man who apparently froze to death. Prodded by the suspicions of his partner, Maureen Kaplowitz, who is famed for the accuracy of her hunches, McKenna uncovers a pattern of murder. His first surmise is that the killer, who calls himself Hyde in a note sent to the cops, is avenging himself on those who gave him AIDS. But the real motive is as surprising as everything else in this well-written tale-countless times, McKenna's initial judgments are proven wrong, usually because he has underestimated everyone from Maureen to Heidi Lane, a sexy young TV reporter who has more on her mind than the news. Even the killer turns out to be more than a maniac out for vengeance. This frequent exceeding of expectations gives Mahoney's tale the high energy of comedy, boosted by sharp, fast-moving dialogue that advances the plot. The result is smart, brisk entertainment.”

According to one reader of Black and White, “NYC Detective First Class Brian McKenna is paired with another McKenna to investigate the torture murder of the daughter of a prominent city councilman. Clues found from the first murder lead to other similar murders across the globe, and the two McKenna's work with a multitude of police departments to track down the killers. The double meaning of the title is finally revealed about half way through the plot. A few of the characters the two McKenna's come across are not as believable as the plot leads, but Brian McKenna continues to be written realistically as someone who solves crimes through hard work and gut instinct, while thoroughly understanding the intricacies of a political NYC police force. Mahoney, a former NCY police captain, is not one to sympathize with the killers in his novels, and offers the readers a straight line plot that keeps the reader interested until the final pages.”

Publisher’s Weekly said of The Edge Of The City, “Former Marine and former NYPD detective Mahoney first caught our attention with Detective First Grade, his tough and funny debut thriller about an unusually interesting cop named Brian McKenna. In that book, McKenna led the NYPD in a five-day war against a decidedly nasty bunch of terrorists -- using somewhat unorthodox methods which didn't please certain superiors. In his second outing, just reprinted in paperback, McKenna has been forced into an early retirement in Florida. But when another band of determined villains (from Peru this time) try to hold New York hostage, guess who gets the call to report back to work. Good, dirty fun.”

According to one reader of The Edge Of The City, it “is an amazing book. It makes all the character's come to life and it was something I easily related to. Since I live on Staten Island, and take the ferry very often I got a really vivid picture of the dilemma. Even the characters seem real. The mayor in the book is a lot like Mayor Giuliani and the police commissioner is very much like former Commissioner Bratton. Overall the book is a must to any mystery/action lover and hopefully Mr. Mahoney will continue to write for many more years. To be honest I bought the book because Mr. Mahoney was a graduate of John Jay, which is the school I am attending now, but now I am hooked!”

According to one reader of Detective First Grade, “I enjoyed this book, partly because of the fact that I served as a detective in the NYPD's major case squad for three and a half years. The procedural details and even the operational details were well crafted and added to the book's authenticity. The chief of detectives was much like the man i served under and the man referred to as a dog's reproductive organ was a lot like the man who I worked for when I was in the Special Investigations Division. In all, Mahoney's tale of cop life was both authentic and very entertaining. I recommend this book to any former cop(like myself) or anyone who enjoys police fiction.”

According to the book description of Justice, “New York City. A wealthy businessman meets a violent fate in his elegant, carefully-secured home in Queens. Two drug dealers are murdered in a Brooklyn no-tell motel room. Several men are found riddled with bullets and nails on a little-traveled road beneath FDR Drive. And soon thereafter, a church, a synagogue, and a mosque find bags of cash waiting at their doorsteps-all from a vigilante who signs himself "Justice."

NYPD Detective First Grade Brian McKenna and his partner, Cisco Sanchez (the self-described world's greatest detective), are assigned to find the elusive killer that all of New York City is rooting for, a man of supreme technical skills, physical power, and intelligence, who always seems to know every move the police will make before they make it. Justice is executing drug dealers, helping the police close unsolved cases, providing those in need with stolen drug money, and creating a nightmare for the police commissioner, the mayor, and the two detectives. As McKenna and Sanchez work to try and outsmart the vigilante and discover his next victim, they also must find out who is helping Justice in his quest for revenge.”

According to one reader of Justice, “A good police procedural. Dan Mahoney's story telling seems to be made for the big screen, but in his writing you get a much better idea of a character's true self. The story moves at a good pace, while the action and drama will keep you going to the very last page.”

Booklist said of The Two Chinatowns, “Cisco Sanchez, who considers himself the best detective in the NYPD, is in Toronto for an interdepartmental boxing tournament. He's smart and tough, but that isn't enough to prevent tragedy when his lover, Sue Hsu, is murdered by members of a street gang as the couple dines in a Chinese restaurant. Sanchez kills the two men directly responsible, but he wants revenge on the gang leader who ordered the hit, to which he and Hsu were innocent bystanders. Despite his personal stake in the case, Sanchez becomes a key member in a joint Toronto-New York strike force charged with dismantling the two key gangs involved in trafficking illegal aliens. One by one, Sanchez and his crew arrest the street soldiers until eventually they find someone willing to turn on the well-protected superiors. Mahoney, who retired as a captain after 25 years in the NYPD, knows the nuts and bolts of a sweeping multijurisdictional police operation. He is also able to portray complex, believable characters struggling mightily with their own muddled lives. Fans of William Caunitz, Robert Daley, and Ed McBain will savor this top-drawer procedural.”

According to one reader of The Two Chinatowns, “This is well written by an author who knows his subject. Dan Mahoney worked as a policeman for 25 years before retiring as a captain. This novel is written carefully with the smallest detail covered. It is a tragic adventure that covers two cities in two different countries in America with the exciting final in Hong Kong, Singapore and Guam. Cisco Sanchez the star in the story claims to be the best detective in New York. Besides, he is a boxer for the New York police team and an actor in the ring who has never lost a fight.

Cisco saw Sue Hsu the woman he wanted to marry. She was an airline hostess. As usual he planned every move to meet her under the best of circumstances. He even took a flight she was working before introducing himself. Everything worked as planned except she was killed by a group of Chinese, part of the `Born to Kill' street gang. She accidentally got in their way on the way to the ladies toilet. Sue had taken Cisco to visit her Chinese Uncle's restaurant in Toronto when it happened. Cisco swore that he would not rest until all the people concerned with her death were taken down.

Cisco discovered that The Chinese gangsters who contracted the `Born to Kill' street gang were heavily involved with smuggling illegal Chinese into New York and Toronto by way of containers ships from China. The novel grows from there to the climax at the end in Guam. For ones who are interested this book has some very interesting part facts about smuggling Chinese and other Asians into America. It is a very dangerous, interesting and a lucrative business. Life is very cheap in this novel.”

The Library Journal said of The Protectors, “Carmen de la Cruz, the richest woman in Spain and a leading voice for peaceful negotiation with Basque separatists, is kidnapped in a violent confrontation while on her way to dedicate a new church. Meanwhile, the Spanish ambassador to the U.S. is snatched in front of his Fifth Avenue residence, leaving two men dead. NYPD detective Brian McKenna is on the scene in New York and is subsequently assigned--along with his partner, Cisco--to a joint task force headed by the FBI. The case has a personal element for McKenna. He's a close friend with de la Cruz, on the basis of a previous case in which her husband was killed. The investigation eventually takes McKenna and Cisco to Spain, where they find moral ambiguity rather than clear-cut answers. Mahoney, a retired, 25-year veteran of the NYPD, has the procedural elements locked down tight, and in McKenna and Cisco he has created a pair of the most likably dangerous cops in current crime fiction. The locales--New York City and Spain--are nicely rendered, and the conclusion is both surprising and satisfying. Fine reading for those who like their crime dramas complex, authentic, and played out on an international stage.”’

The School Library Journal said of Detective First Grade, “Veteran NYPD detective Brian McKenna has a knack for spotting concealed weapons, so when he spies a suspected gunman in a Brooklyn housing project, he gives chase. This leads to a gunfight, and the suspect is killed. The trail from the dead man leads to Cuban drug dealers and a hushed-up hostage/ ransom negotiation. Kidnapping and international terrorism are the basis for this fast-paced police procedural. The story is tightly written with realistic situations and colorful dialogue. It abounds in strategic details, but subplots involving McKenna's desire for promotion and his friendship with the Chief of Detectives enrich the plot and rescue it from being too tedious. The only flaw is a lack of well-drawn female characters. The token women are minor-role police officers, occasional wives and girlfriends, and one tough, vengeful terrorist.”