D.A. May Ask Death Penalty for Ex-Worker : Courts: Fired worker Robert Earl Mack pleads not guilty in the slaying of a company labor negotiator and the wounding of his ex-boss at General Dynamics.

The man accused of killing a company labor negotiator and critically injuring his former boss at a San Diego General Dynamics plant last week pleaded not guilty Tuesday. The prosecutor in the case said he may seek the death penalty.

Robert Earl Mack, 42, has been charged with murder in the death of Michael Konz, 25, a General Dynamics labor negotiator studying to be an attorney, and attempted murder in the shooting of James English, 52, Mack’s former supervisor.

In his first court appearance since Friday’s shooting at the Pacific Highway plant, Mack was ordered held without bail by San Diego Municipal Judge David J. Danielsen.

Mack, who appeared in court with his hands tucked into a dark blue jail-issued jumpsuit, said nothing during his short arraignment.

Fired from his job Jan. 15 as a machinist at the defense contracting firm where he had worked since 1968, Mack shot both men in the back of the head Friday after a grievance hearing, police said.

English is making a rapid and remarkable recovery at UC San Diego Medical Center and Tuesday was listed in fair condition.

In court Tuesday, prosecutors said they may file special circumstance charges against Mack, which could lead to the death penalty.

“This is potentially a capital case,” Deputy Dist. Atty. Robert W. Sickels told the judge as he argued against bail for Mack.

After the arraignment, Sickels said there is evidence that Mack was “lying in wait,” a legal categorization that, if proven, can lead to either death in the gas chamber or life in prison without the possibility of parole.

The district attorney’s office typically waits until a defendant’s Superior Court arraignment to file special circumstance charges, about two weeks after a preliminary hearing in the case. Mack’s preliminary hearing is set for Feb. 10.

Mack’s defense attorney, J. Michael Roake, raised the possibility that his client may later change his plea to not guilty by reason of insanity. Roake said “one of the options” is subjecting Mack to intense psychiatric review to determine if he was competent at the time of the shooting.

While the insanity plea is a possibility, Roake would not elaborate on his defense strategy.

“It’s absolutely too early to tell--there’s a whole spectrum out there,” he said.

Roake said he will try to persuade Danielsen to set bail during Mack’s next appearance in court Friday.

Meanwhile, classmates of Michael Konz at the University of San Diego, where he was studying law at night, gathered Tuesday night for a memorial Mass and began plans to finance a scholarship fund in his name.

Konz, an Arizona State University graduate, was hired at General Dynamics in 1988 as a human relations counselor. His job was to represent management in labor disputes, and he was performing that role at Mack’s grievance hearing.

Known as a hard-driving young executive with a touch of arrogance, Konz was nevertheless revered by his USD classmates, who appreciated his special brand of humor and ability to ease tension in the classroom.

One criterion for the scholarship will be to measure the applicant’s sense of humor, said classmate Luke Ryan, because Konz was so amusing.

“He was always up and he cheered us up,” Ryan said. “He was a positive influence in the class and we will never forget him.”

Konz was always available on Thursday nights--class did not meet on Fridays--for an after-class beer and good conversation, classmates said.

“Mike felt that his friends at law school were his special friends,” Ryan said of the class, which numbers 79. “He was an excellent student, one of the top law students in our night division, despite the fact he worked 50 hours a week at his job.”

Ryan said Konz was midway toward a law degree.

Times wire services contributed to this story.