A man accused of using dynamite to blow up a truck and its driver in Baltimore last month was arrested yesterday by U.S. agents who used an experimental system to trace the explosives.

James L, McFillian, 56, of Baltimore was arrested in Martinsburg, W. Va., by agents of the Bureau of Alcohol, Tobacco and Firearms.

He was charged with maliciously damaging a truck by means of an explosive causing the death of Nathan A. Allen Sr., 46, and with interstate transportation of explosives without a license. Allen was killed in the parking lot of the Bethlehem Steel plant where he worked.

Bruce Tibbo, a spokesman for the federal enforcement agency, said agents looked for and found tiny plastic particles in the debris of the explosion. The composition of these particles, placed in explosives for the purpose of tracing them to their manufacturers can disclose where, by whom and when an explosive was manufactured.

"After that it's just like tracing a gun," said Tibbo. "There are records which lead from the manufacturer to the retailer to the purchaser who has to sign something to buy them."

The experimental explosives identification program would be mandated by law under the Anti-terrorism Act now pending in Congress.

McFillian could receive the death penalty if convicted, according to Tibbo. He was held under $250,000 bond.

According to court documents filed in connection with the case, McFillian and Allen had a dispute over a woman.