The conviction of five South Jersey men for plotting to kill soldiers at Fort Dix was a fair verdict that highlighted the difficulties of prosecuting an anti-terrorism case before any shots are fired.

The five Muslim immigrants were convicted by a federal jury in Camden of conspiracy, but acquitted of attempted murder. Four of the defendants were found guilty of illegal weapons charges.

They face a possible sentence of life imprisonment. Prosecutors intend to seek that maximum penalty for brothers Dritan, Eljvir and Shain Duka, illegal immigrants from the former Yugoslavia living in Cherry Hill; Mohamad Shnewer of Cherry Hill, a U.S. citizen born in Jordan, and Serdar Tatar of Philadelphia, a legal U.S. immigrant born in Turkey. All the men are in their 20s.

The FBI probe began in January 2006, when a courageous electronics-store clerk turned over to police a customer's videotape showing the men firing rifles and shouting Islamic phrases at a target range. Agents used two paid informants to infiltrate the group, monitoring the suspects and recording their conversations during the next 15 months.

Federal authorities said the men obtained weapons and discussed attacking other military installations besides Fort Dix, including the U.S. Coast Guard building in Philadelphia and Dover Air Force Base in Delaware. They were arrested in May 2007 as the informants arranged to sell them assault rifles.

A principal question that had to be decided by the obviously diligent jurors was this: were the young men simply engaged in harmless talk, or were they seriously plotting a terrorist attack? The verdict shows, correctly, that the group's actions went beyond mere talk.

Shnewer drove with an informant to the gate at Fort Dix and discussed how to attack soldiers there. He also proposed firing a rocket into the Philadelphia Naval Base during the Army-Navy football game.

Tatar gave one of the informants a map of Fort Dix and told him, "I'm in." Although he initially told Philadelphia police about the informant, he lied about delivering the map.

Prosecutors acknowledged that the group had not settled on a target, or a timetable for a possible attack. Federal authorities had a duty to err on the side of caution in nabbing the men in the planning stages.

What probably started out as "big talk" among disaffected young Muslim men went too far. And while the FBI used an unsavory character to infiltrate the group, agents had a responsibility to find out if there was a real plot and, if so, to stop it.

Relatives and supporters of the defendants accused the justice system of bias against Muslims. The charge appears to be unfounded. Given the evidence, prosecutors should have moved against five young men of any faith or background who were involved in the same activities.

Maybe these five defendants would have proved too inept to carry out an attack. But that doesn't mean they lacked those intentions or didn't take steps to do so. Justice was served in this case.