A physicist, an inventor and an aerospace scientist, Jack Cover was best known for his invention of the Taser stun gun. The weapon, which delivers a powerful electric shock, is now used by many of the world’s police forces to subdue suspects.

Cover named his device Taser as an acronym for Thomas A. Swift’s Electric Rifle; Tom Swift was his childhood fictional hero. He developed it to provide law enforcement agencies with a non-lethal weapon to help them to confront the civil violence of the 1960s.

Cover had read the report by President Lyndon Johnson’s Blue Ribbon Crime Commission that urged the development of non-lethal weapons to combat the hijacking of aircraft, riots and civil unrest happening at that time.

Tasers, which are manufactured by Taser International, Scottsdale, Arizona, use pulses of electrical current to disrupt the target’s ability to control his or her muscles. Designed for use against fleeing or potentially violent or aggressive subjects, the battery-

operated device projects darts attached to insulated wires to deliver electric shocks over a range of up to a few metres. The target’s sensory and motor nerves are stimulated by the shocks, producing strong involuntary muscle contractions.

Taser International markets two police models, which can be fitted with laser sights, and a model for civilian use. Between 1976 and 1995 the Taser darts were propelled by gunpowder, and many countries classified the devices as firearms. Cover then modified the weapon so that the darts were propelled by compressed air. The modified Tasers, caller Air Tasers, could then legally be sold to the public in some countries.

More than 13,400 law enforcement, correctional and military agencies in 44 countries now use Taser guns, according to Taser International’s website. They are available to more than 375,000 police officers. In addition, more than 180,000 Tasers have been sold to private citizens. Tasers are, however, controversial weapons, particularly because they are used so frequently. Amnesty International, for example, argues that the use of Tasers by private individuals should be banned and their use by police limited.

Critics point out that in the past eight years more than 330 people have died after being subdued with Tasers by police officers. But it is unclear whether the Taser was directly responsible for any of the deaths. Nevertheless, the American Civil Liberties Union wants Tasers classified as deadly weapons. But Cover himself believed that the benefits of Tasers outweighed any costs, arguing that his invention has saved about 100,000 lives. Police forces, in general, support their use.

John Higson Cover, always known as Jack, was born in New York in 1920, and grew up in Chicago. His father was Professor of Economics at the University of Chicago, and his mother earned a master’s degree in mathematics at the same university.

Jack Cover studied at Chicago too, receiving his bachelor’s degree and a PhD in physics; his professors included the eminent nuclear physicists Enrico Fermi and Edward Teller.

During the Second World War Cover served in the US Army Air Force as a test pilot. After the war he worked for several years at the Inyokern Naval Ordnance Test Station, China Lake, California. He spent most of the rest of his career working in the aerospace and defence industries.

From 1952 to 1964 he was employed as a scientist by North American Aviation (which later became Rockwell International), in charge of the company’s group of researchers working on the Apollo space project that landed men on the Moon. His work in the early 1960s helped the company to become a primary contractor for Nasa on the Apollo programme. He stayed with that programme until it reached fruition on July 20, 1969, when the astronauts Neil Armstrong and Buzz Aldrin landed on the Moon.

After leaving North American Aviation, Cover worked for IBM and the Hughes Company in California. In 1970 he set up a company, Taser Systems, to exploit his invention of the Taser stun gun.

Cover married three times. His first two marriages ended in divorce. He is survived by his third wife, a son and three daughters.

John Cover, physicist and inventor, was born on April 6, 1920. He died on February 7, 2009, aged 88