Alexis Yamil Perez, a 19-year-old Pleasantville resident, was shot and killed by police a week ago. Three officers had responded to a call of an armed man making threats. They found Perez wielding a knife when they arrived.

What happened next is now the subject of an investigation by the Atlantic County Prosecutor's Office. Acting Prosecutor Jim McClain said Perez was shot multiple times by police. But other than that, it will take a thorough investigation to determine whether the shooting was justified.

But this much is clear: If police officers at the scene had been armed with a conducted-energy device, commonly known as a stun gun, Perez might still be alive.

The use of stun guns by New Jersey police departments has a somewhat tortuous history. As recently as 2009, police officers in New Jersey were banned from using the devices. Indeed, New Jersey was the only state that still banned law enforcement from using the weapons.

The attorney general in 2009, Anne Milgram, changed that policy, allowing police to use stun guns in a very limited set of circumstances. The policy proved too restrictive, and no police departments purchased the weapons.

In 2010, Attorney General Paula Dow sensibly loosened the policy, allowing officers to use the weapons to prevent a suspect from killing or seriously injuring another person, an officer or himself or herself. She also required that any officer authorized to carry the devices undergo mandatory training developed by the state's Police Training Commission.

But now, almost four years since they were first authorized, stun guns are still not in widespread use in New Jersey.

In Atlantic County, for example, while eight agencies have purchased the devices, no agency is yet authorized to use them. No officers have been trained in the use of the devices, and a countywide policy regarding their use has not yet been issued, according to the Prosecutor's Office.

Stun guns would seem to be useful, less-lethal weapons that could help save lives in dangerous situations. Indeed, police lobbied for the approval of stun guns in the state. Now the law-enforcement community seems to dragging its feet on authorizing and implementing the use of these devices.

The two Taser International Inc. models approved for use in New Jersey cost from $800 to $1,500 - not a particularly exorbitant amount.

It is disappointing that the use of these devices - in appropriate circumstances - is not more widespread.