Federal authorities have arrested three people accused of arming gang members and street criminals with more than 1,700 handguns over the past four years. James Larry Simmons, a 55-year-old truck driver from Temecula, was indicted on 21 counts of federal firearms violations, the Bureau of Alcohol Tobacco and Firearms announced. Lynnette Groves, 62, of Whittier and Sambeth So, 28, of Long Beach, were also charged. "We've probably eliminated several future murders and assaults by taking this guy off the streets, but God knows how many will happen from the guns he already peddled," said Ismael D. Cabrera, head of the ATF office in Santa Ana. Simmons' lawyer said the indictment, handed down Thursday by the federal grand jury in Los Angeles, amounted to little more than poor record keeping.