Lavdimir Ibrahim gave a brief account of his actions to an investigating magistrate, in which he reportedly admitted to his role in the fatal shooting of the prominent criminal lawyer.
Greek police are seeking a second Albanian national who is on the run, and is believed to have already escaped to Albania.
Police believe that the two suspects were hired by an Albanian crime gang to intimidate the lawyer.
Their orders had been to injure the lawyer by shooting him in the legs, police said, but for some reason they shot him in the chest.
The masterminds were three inmates in a Greek jail who intended to extort 5 million euros out of a jailed power firm executive, by threatening Zafiropoulos, who was his lawyer.
Alternate Citizen Protection Minister Nikos Toskas hailed the Greek Police for solving the case.
“We had made it clear from the first moment that the battle against crime is among our priorities, particularly homicides and drugs,” he told the Athens Macedonian News Agency.
“Greece is an area of stability and safety, which is a result of its foreign policy and also the way that common crime is tackled within the country”, he added.
Toskas claimed that “there has never before been such rapid reaction in police operations and this is not accidental. Miracles do not happen in these fields. It is the result of systematic work and good organisation”.