Two cases under section 25 of Arms act have been filed in the court against the accused juvenile, who is lodged in Varanasi jail, police said.
On February 16, gangster Vicky Tyagi was fatally shot dead by the armed juvenile, who had entered a courtroom here masquerading as a lawyer.
The accused was arrested on the spot and the pistol used in crime recovered from his possession, they said.
Later, one more firearm was recovered from his residence here, they said.