An American Vietnam War veteran, who was arrested by troops after illegally crossing Cambodia's heavily defended border last year, has been released from prison in Phnom Penh, officials said Tuesday. The officials, who asked not to be identified, said Sterling Brian Bono, 36, of Las Animas, Colo., was staying at the State Guest House after his release earlier this month. They said he has been staying in the mansion with spacious gardens, a former residence of the French colonial governor, while the International Committee of the Red Cross arranged for a family member to come to Phnom Penh to pick him up.