A Montgomery County jury yesterday sentenced James Arthur Calhoun, 28, to die in the Maryland gas chamber for the March 27 murder of county police officer Philip C. Metz.

Calhoun was convicted by the same jury on Tuesday of killing Metz during an early morning robbery at the W. Bell discount store in White Oak. A security guard also died in the robbery.

The jury deliberated for six hours whether the sentence should be death or life imprisonment. The death sentence was the first in Montgomery under a 1978 law.

Assistant State's Attorney Barry Hamilton argued strongly for Calhoun's execution, telling the jurors, "You're not being asked to act in some manner as gods. You're asked to make a legal determination" whether Calhoun met the criteria for execution.

That criteria, Hamilton said, included the fact that Metz was an on-duty police officer and that the murder was committed during a robbery. Hamilton said that there were no mitigating factors in Calhoun's case since Calhoun had a criminal record with six convictions.

Defense attorney Courtland K. (Skip) Townsend asked the jury to spare Calhoun's life because Calhoun was a product of society and that the death penalty was uncivilized.