LAWRENCE, Mass. — A 15-year-old boy charged with killing a high school classmate whose headless body was found near a river said in a police report made public Monday that they had gone to smoke marijuana together and he had last seen the classmate alive. Mathew Borges was held without bail after pleading not guilty at his brief arraignment in Lawrence District Court on a murder charge. Borges is being prosecuted as an adult, so court proceedings were open. His lawyer, Edward Hayden, did not argue for bail. The body of 16-year-old Lee Manuel Viloria-Paulino was found near the Merrimack...