The family of a 14-year-old Beit Shemesh youth who was violently assaulted by police last week after resisting arrest is filing an official complaint, the boy's father said Thursday. The teenager, who was apprehended for allegedly setting a field on fire, was filmed by a passerby being beaten and dragged into a police van while resisting arrest. The incident, which was broadcast on Israel's top-rated evening TV newscast on Channel 2, was the latest flare-up in tensions between police and residents of the city. Jerusalem police spokesman Shmuel Ben-Ruby said Thursday that police used "appropriate" force against the intoxicated teen. "The pictures speak for themselves and reveal the lies and embarrassment of police," said Hanan Kabiri, the boy's father. "The police force in Beit Shemesh is known for their violence against all sectors of the public, and this time it is on tape," he said. The teen, who was later found to be carrying a pocket knife, denies any involvement in the arson. Kabiri said that the family's lawyer is filing an official complaint on Sunday with the Justice Ministry's Police Investigations Department. "We will pursue this until justice is served," he said.