Seeking Answers After Youth's Death in Police Stop BAY HARBOR ISLANDS, Fla. - Israel Hernandez-Llach, a skateboarder and 18-year-old artist, was typically adept at dodging police officers while he tagged Miami Beach walls with his signature, "Reefa." But early Tuesday morning, after he rolled up to a shuttered McDonalds, his lookout with him, the police caught up with the teenager. Mr. Hernandez-Llach bolted, running through the streets and a building and over an iron fence, according to a report by the Miami Beach police. The officers ultimately stopped him, after firing a Taser to immobilize him, said Raymond A. Martinez, the Miami Beach police chief. At 6:15 a.m., an hour after the police first spotted him, Mr. Hernandez-Llach, a former Miami Beach High School student and a Colombian immigrant, was pronounced dead at a nearby hospital. The teenager was in medical distress after being shocked by the Taser, Chief Martinez said, and paramedics were called. Chief Martinez said that the cause of death had not yet been determined and that the department was waiting for autopsy and toxicology reports. Mr. Hernandez-Llach had no other injuries, the police said. The department is investigating. On Thursday, Mr. Hernandez-Llach's parents held a news conference and called for an independent investigation. The family's lawyers pointed out that had Mr. Hernandez-Llach been arrested he most likely would have been charged with criminal mischief, a misdemeanor that seldom ends in jail time. The teenager's only previous arrest had been for shoplifting, the police said. "Those guilty of this must be brought to justice," said his father, Israel Hernandez Bandera, who was a former Avianca pilot in Colombia, holding back tears as he spoke. Not even animals deserve that kind of treatment. A friend of Mr. Hernandez-Llach's, Thiago Souza, 19, who served as the lookout on Tuesday, said he saw the police officers giving each other high-fives after deploying the Taser. Family and friends called for a vigil on Thursday night and for two more vigils on Saturday at the location where Mr. Hernandez-Llach was shocked with the Taser. They are also trying to raise money for his funeral, relatives said. "Art is nothing to be killed for," said Offir Hernandez, 21, the teenager's sister. The Miami Beach Police Department has faced scrutiny in recent years after a string of shootings and misconduct involving its officers. During Memorial Day weekend in 2011, eight Miami Beach police officers fired more than 100 bullets at an intoxicated motorist who was driving recklessly. Four Hialeah police officers also were involved. The motorist was killed and four bystanders were wounded. More than two years later, the case is far from resolved. The Miami-Dade state attorney is weighing whether to bring charges against the officers. Tasers are used by an estimated 17,000 law enforcement agencies around the world to subdue people who pose a threat, according to Steve Tuttle, a spokesman for Taser International. A 2011 Department of Justice report found that the devices are considered safe for a vast majority of those who are subjected to them and can save lives by immobilizing suspects. Taser use results in few injuries, the study found. Although people have died, the risk is extremely low, the report stated. Often, deaths are associated with pre-existing medical conditions, drug use or a subsequent fall. Continuous or repeated shocks are also associated with deaths, the report stated. An estimated 500 people have died after being shocked by Tasers since 2001, according to data compiled last year by Amnesty International. Jacqueline Llach, Mr. Hernandez-Llach's mother, described her son as frail; friends said he was skinny and about 5 feet 10 inches. "The police could have done what they needed to do without killing him," she said in her apartment, where friends had gathered to console the family. Even in his native Barranquilla, Colombia, Mr. Hernandez-Llach had a knack for art, friends said. His talent flourished when he arrived in the United States. At Miami Beach High School, he won awards for his painting and recently had two sculptures accepted in a temporary exhibit at the Miami Art Museum, said Savannah Diaz, a friend and fellow student. His artwork was on display at his parents" apartment in Bay Harbor Islands, just off Bal Harbour. The teenager, who enjoyed pushing the boundaries of self-expression, also gravitated to photography and graffiti, Ms. Diaz said. She said he and his helpers would look for wall space in different corners of Miami, including Wynwood, which is known for its graffiti art, and Broward County. Ms. Diaz, who graduated this year, said that her friend was not aggressive. "Israel is the most creative person any of us had ever met," she said. His life revolved around art and skating. Recently, he had started designing specially shaped skateboards. This May, when friends graduated from Miami Beach High, Mr. Hernandez-Llach was not one of them. He had failed physical education, a subject he disliked, friends and family said. "That's Israel," Ms. Diaz said. P.E. wasn't a priority. It was about his art work. Nick Madigan reported from Bay Harbor Islands, and Lizette Alvarez from Jacksonville, Fla.