Drug Enforcement Administration and Colombian officials claim last week's murder of DEA Special Agent John "Terry" Watson was a robbery-gone-bad.

But new details in the case suggest the federal agent working on sensitive and high-profile drug cases in Colombia could have been the victim of a targeted attack. Colombian authorities have arrested four men in connection to the killing.

"It sounds more like a hit than a robbery," Phil Jordan, a former CIA operative and one-time leader of U.S. Drug Enforcement Administration's El Paso Intelligence Center, told Fox News Latino. "There's a lot of questions that need to be answered."

Watson, a 43-year-old Louisiana native, was killed after being dragged out of a taxi on his way home from a Bogotá restaurant late last Thursday night after watching the NBA Finals game.

In what both U.S. and Colombian authorities initially called a botched robbery, Watson was stabbed three times in the chest and once in the leg. He was pronounced dead after arrival at a local clinic.

"We have nothing right now to suggest this was anything other than a random crime," said DEA spokeswoman Barbara Carreno. "We are still in the midst of investigating the incident."

Police in Colombia were reviewing area security cameras in hopes of identifying the assailants. The police department has offered a reward of 50 million pesos -- about $25,800 -- for information leading to the arrest of those responsible.

But Colombian media have raised questions about whether the killing was tied to Watson's work in Colombia – and whether the attack was in retribution for DEA investigations into high-level drug operations in the Latin American nation.

Yet the country's police director told the leading Colombian newspaper El Tiempo that officers had infiltrated the criminal gang and concluded the murder was not tied to Watson's investigations.

Watson, a 13-year veteran of the agency, was assigned to the coastal city of Cartagena, but was in the Colombian capital on temporary duty.

The Colombian newspaper El Tiempo reported that Watson was a key agent in the arrest and extradition of drug trafficker Hipolito Martínez Felipe González and his network, who operated out of the Gulf of Urabá near Colombia's northern border with Panama.

Local authorities have said the killing was a "paseo millonario," or express kidnapping.

But Jordan said the so-called "paseo millonario" robberies usually don't end up with the victim being killed.

A common tactic in Colombia and other cities throughout Latin America, a "paseo millonario," where victims are forced to use their ATM cards to empty their bank accounts. The assailant will target people driving expensive cars or leaving upscale neighborhoods for robbery.

Watson's murder seems suspect because the robbers did not take off with his cell phone or any other personal items.

'The problem here is that when you're going to rob someone you normally just rob them and don't kill them," Jordan said. "The story line seems farfetched."

Colombian authorities announced on Tuesday that they had detained four suspects in Watson's murder. Two were arrested in Bogotá, one in the neighboring Tolima department and another in the city of Villavicencio.

No additional information about the arrest was provided, other than that there are still two more arrests warrants out in connection to Watson's killing.

Watson's body was flown back to Louisiana on Monday, where the state police and state Wildlife and Fisheries honor guards escorted his body from Monroe Regional Airport to his hometown of Rayville. A service is scheduled at Rayville High School for Wednesday morning.

"Terry dedicated his life to serving the public and making the world a safer and better place," Watson's family said in a statement. "Terry never wasted a minute of his life and never took it for granted. We are sad that he is gone but are incredibly proud of his service and the type of person he was. We will always love him dearly."

Watson is survived by his wife Fadia, his mother and father, Paul and Henrietta, and his brother, Scott, a lieutenant for the Louisiana Department of Wildlife and Fisheries.

Follow Andrew O'Reilly on Twitter @aoreilly84.

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