FORT LAUDERDALE, Fla.—A former Marine sharpshooter accused of invading the home of apparent strangers in Florida and fatally shooting a woman, her 3-month-old baby, and two others was ordered held without bail during his first court appearance Monday. Authorities did not give a motive for the grisly attack, but they said Bryan Riley may have a mental illness and that he told investigators he was high on methamphetamines at the time. At his court appearance Monday, Riley, 33, said that he intended to hire a lawyer, but one will be appointed for him in the meantime. Riley surrendered on Sunday morning after a furious gunbattle with authorities who brought in at least one armored vehicle during their standoff. After it was over, an officer rushed into the home and rescued an 11-year-old girl, who was still conscious despite being shot seven times. She was in critical condition on Monday, the …