Reputed mobster Nissim Alperson was arrested Sunday along with an additional 19 suspects during a police raid in the Ramat Gan financial district.
Dozens of undercover detectives swarmed a restaurant where Alperon was dining and during a subsequent search of a scooter belonging to an associate of Alperon, found a pistol.
The detectives were accompanied by officers from the Israel Police Special Patrol Unit.
The suspects were taken in for questioning and will face remand hearings in the morning.
Police are probing whether or not the weapon was to be used to carry out a crime at a later time.
Nissim's brother crime kingpin Ya'akov Alperon was killed in mid-November when his private vehicle passed over a bomb at the corner of Pinkas Street and Namir Road in north Tel Aviv. He was on his way home from court, where two of his sons had their remands extended for alleged threats and extortion.
Tel-Aviv police called the hit "an earthquake for the underworld."
Another of Yaakov's brothers, Zalman Alperon on Sunday had harsh words for his brother's killers, but pledged that his family is not seeking revenge for the daylight assassination.
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