LAS VEGAS—Prosecutors in Nevada filed additional charges and told a judge on Monday a grand jury may review evidence that a Las Vegas man held a woman and her children captive, killed her 4-year-old son, and hid the body in a garage freezer. Brandon Lee Toseland’s appointed attorney, Scott Coffee, noted outside court that medical examiners have yet to release findings of the boy’s death and prosecutors have yet to share with him evidence collected since Toseland’s arrest last week. Toseland was taken into custody Feb. 22 in a vehicle with the child’s mother after a 7-year-old schoolgirl gave her teacher a handful of sticky notes saying her mother was being held captive and thought the girl’s brother was dead at Toseland’s house. Police said they found handcuffs with the woman in the car. The boy’s frozen body was found wrapped in plastic bearing what police Lt. Raymond Spencer said …