Mexico City - Mexico's best-known political murder trial, which has swung between deadly seriousness and high farce, has taken new turn. Raul Salinas, the brother of former President Carlos Salinas, wrote to London-based Amnesty International from the cell where he is held on murder charges to complain that his human rights had been violated. Salinas has been held since his arrest in February 1995 on charges of illicit enrichment and plotting the 1994 murder of Jose Francisco Ruiz Massieu, a top ruling party politician.