The parents of a 21-year-old Charlotte man who died after being shocked by a Taser in July 2011 have sued the city of Charlotte, police and Taser International.

The lawsuit, filed in federal court on Tuesday, alleges that Charlotte-Mecklenburg police Officer Michael Forbes used excessive, deadly force when he shocked La-Reko Williams twice with his department-issued stun gun at the Woodlawn Lynx light-rail station.

Williams died just a day after a federal jury in Charlotte awarded $10 million to the family of 17-year-old Darryl Wayne Turner, who died in 2008 after a CMPD officer shocked him with a Taser. It was the biggest jury award ever against Taser International.

The city had previously paid $625,000 to Turner’s family but denied wrongdoing. It was the largest police-related claim the city had paid in nearly a decade.

The most recent lawsuit calls Tasers potentially deadly weapons and says that CMPD officers should only use them when a confrontation calls for deadly force.

In a statement, CMPD attorney Mark Newbold said: “We are preparing a defense to the claims made within the suit filed today in Federal Court by the estate of Mr. Williams. Although Mr. Williams’ death was indeed tragic, we believe that the actions taken by the officer were lawful and appropriate under the circumstances.”

Williams’ parents claim their son was shocked by the Taser during an altercation between Williams and his girlfriend, Destiny Franklin.

Police said when the officer arrived at the station, Williams was beating and choking a woman.

But the lawsuit says Williams, who stood about 5 feet, 6 inches and weighed about 145 pounds, was unarmed and presented no threat to the officer. Williams was shocked twice in the chest, suffered cardiac arrest and died within minutes, the lawsuit says.

After Williams died, police suspended their use of Tasers for six months as they investigated the safety of the weapons. In September 2011, the City Council approved $1.83 million to buy new Tasers.

The new Tasers, which police use today, still shoot out 50,000 volts of electricity to incapacitate suspects, but have features designed to prevent officers from injuring or killing suspects. Most importantly, they automatically cut off after five seconds, even if the officer continues pulling the trigger. Police determined that people who were shocked have died when an officer held down the Taser trigger for too long, and said the new Tasers are safer.

Police have not said how much time elapsed while Williams was shocked. The lawsuit alleges that Tasers used by CMPD officers “are deadly weapons that cause cardiac arrest and death.”

Williams’ parents allege that Forbes used his Taser in an inappropriate and excessive manner before considering less deadly uses of force against their son.

The lawsuit faults police training, claiming officers have been taught to use Tasers before using physical force.

Williams’ parents are asking a judge to permanently prohibit CMPD officers from using Tasers or to only allow the use of the weapons when officers must use deadly force.

Staff researcher Maria David contributed.