PHOENIX — Stun-gun maker Taser International has started telling police agencies to avoid firing the devices at suspects' chests, explaining that there's an "extremely low" risk of ill effects on the heart and that doing so will make defending lawsuits easier.

The Scottsdale, Ariz.-based company made the recommendation in an Oct. 12 revised training manual, saying it "has less to do with safety and more to do with effective risk management for law enforcement agencies." The manual also includes a lengthy explanation about deaths caused by sudden cardiac arrest.

"Should sudden cardiac arrest occur in a scenario involving a Taser discharge to the chest area, it would place the law enforcement agency, the officer, and Taser International in the difficult situation of trying to ascertain what role, if any, (the device) could have played," according to the manual.

The manual includes a graphic displaying the human body and "preferred target areas." The company recommends firing Tasers anywhere but at the head, neck and chest. The manual says to avoid chest shots "when possible" and "unless legally justified."

Taser critics call the company's new recommendation an admission that the devices can cause heart attacks.

"It's a sea change, a passive acknowledgment that Taser has indeed been overconfident about its claims of safety," said Mark Silverstein, legal director of the ACLU of Colorado. "It underscores the question marks that have been adding up along with hundreds of bodies."

Amnesty International says more than 350 people in the U.S. died after they were shocked with Tasers, and that in 50 of those cases, medical examiners cited a link between Taser shocks and death.