Patrick Joseph Murphy helped launder millions of dollars in drug cash and consorted with international cartels, Mexican drug gangs, and dirty cops and politicians.

He worked with white supremacist groups, crooked investment brokers, and gangsters, impressing seafaring drug runners with his two catamarans.

Patrick Joseph Earp was a former banker turned U.S. Treasury agent, a loving father and brother, and a man struggling with personal demons.

When Earp was found shot to death in a relative’s Coconut Grove cottage in February — a single slug to the head from a 9mm Glock — it was also the end of the line for Patrick Murphy.

The two men, different in so many ways, were one and the same.

Earp’s death at age 50 haunts his family and friends, who have been left hanging for months as Miami police and the Miami-Dade Medical Examiner’s office decide whether the shooting of Earp was a suicide or something more sinister. As of Friday, 10 months since his death, the cause and manner of death has not been officially determined.

Adrenaline rush

For 14 years, Patrick Earp lived a double life — working undercover with a phony name, Patrick Murphy, and a fistful of government-issued plastic under that assumed identity.

Standing just 5-foot-9, and sporting a goatee under a shock of thinning brown hair, Earp loved his swashbuckling, surreptitious missions, and lived much of his life on the fringes of the dark and violent criminal world he infiltrated.

“He lived for that,” said his brother, Rob, who discovered the body. “The adrenaline rush, the excitement.’’

A member of a prominent pioneering Miami family — they are also, the family says, related to the famous sheriff Wyatt Earp — he attended a private military boarding school in New Mexico, then graduated from Texas Tech with a degree in business administration. Shortly after college, he met his future wife, Malinda, with whom he would have two children. (Malinda Earp declined to comment for this story).

While Earp began his career in banking, he always dreamed of being a federal agent, and in 1991, he finally got his chance, joining the Internal Revenue Service. Within a few years, he was working undercover on various assignments across the country, fighting in the war against drugs.

In 1998, the IRS assigned Earp to a post in the Keys, as a member of the South Florida High Intensity Drug Trafficking Area (HIDTA), made up of teams of federal and local law enforcement agencies working together to combat drug crime. There was plenty of that in the Keys.

He was a federal agent, pretending to be a legitimate businessman, but one whose real business was working with drug smugglers and money launderers — for the purpose of building cases against them and bringing them to justice.

It can be a mind-bending house of mirrors, making your living pretending to be someone else, but the mission was simple:

Follow the money.

Inside his case files

Records obtained by The Miami Herald reveal that he was responsible for dozens of cases. There was the probe of the Key West city commissioner suspected of channeling millions of dollars in drug money through his businesses; and one involving allegedly corrupt cops with purported ties to Florida City elected officials.

Other cases involved targeting a cartel that trafficked drugs to Florida, then channeled the proceeds to Texas and Mexico through check-cashing businesses.