Though Roman Welzant, a 68-year-old retired salesman, openly acknowledged that he shot and killed an unarmed teen-ager, the jurors at his trial agreed with little debate that he was innocent of murder.

The 10 hours of deliberation Tuesday were necessary because one member of the Baltimore County jury wanted to convict Welzant of assault but finally agreed to join the other jurors in acquitting him.

The jurors' uncertainty about what happened in the moments before the shooting was the key reason for the acquittal, the two panel members said. Welzant testified that the youths were shoving, grabbing and threatening him; the teen-agers who testified denied it.

One juror, Bassil L. Marshall, said he had too much doubt about the exact circumstances of the shooting to find Welzant guilty. And Marshall, the oldest member of the panel, clearly had sympathy for Welzant, who said he was repeatedly taunted and threatened by four teen-agers that night.

"Look, Marshall said yesterday. "I'm 68 years old too, and I wouldn't want the four of them coming after me."

Welzant was charged with killing Albert Kahl Jr., 18, and wounding James K. Willey, 16, Kahl's close friend and next-door neighbor. He faces charges of second degree murder, assault with intent to kill, assault and two handgun violations.

Since the Jan. 4 incident in Eastwood, a working-class community just over the Baltimore city line, the Welzants have received more than 250 sympathetic letters, mostly from other elderly persons and often enclosing small bills that now total more than $4,000.

To these kindred souls across the country, the Welzants' ordeal has come to symbolize the struggle of the aged to maintain their dignity and withstand the assaults, physical and otherwise, of a society that seems geared toward the young.

Welzant's defiant stand that snowy night, its fatal consequences notwithstanding, has turned him into a folk hero for these elderly. It is a role, he said yesterday, which surprises him but which he does not reject.

Some of the letter-writers, he said, relaxing with his wife, Genevieve, in their daughter's back yard in Towson, suggested he should have killed the entire group of about eight teen-agers involved in the night's events.

"I just wonder how their thinking came about, that they would make an expression like that," he said, disapprovingly.

For the Welzants, as for others irreversibly touched by the snowball tragedy, life will never be the same again. They could not move back to their old neighborhood, the couple said, for fear of further attacks. The house would be sold, Welzant said, and the couple would either buy a new house or rent an apartment somewhere else.

After only three hours of sleep, Roman and Genevieve Welzant seemed at rest and at ease. "It's the first time I've seen them smile in a long time," said Martin Welzant, their youngest son.

Given the same set of circumstances, Welzant said without hesitation, he would react the way he did the night of the shootings. "It was just such a flash of action," he said. "Had they smashed me to the ground, I might not have been here."

There are still sleepless nights, Welzant said. His wife, who is anemic, has had trouble eating and sleeping. "I can hear the sounds" of that night, she said. "I wake up and I'm afraid to go back to sleep because I can hear the pounding [on the door] and [Roman] telling me to lock myself in my room. I get up, walk around, smoke cigarettes."

Welzant posed with his arm around his wife, who said, "It's a tragic thing." And Welzant expressed sympathy for the slain boy's mother, who had to be helped from the courthouse after the verdict.

"You could understand," said Welzant, whom Mrs. Kahl had called a killer as she left the courtroom. "Any mother would feel like that."

Neither Frances nor Albert Kahl Sr. were at home yesterday to receive the reporters who descended on their neighborhood. In a lengthy courthouse conversation before the verdict, however, Frances Kahl, a woman in her 40s, painted a grim picture of the impact her son's death has had.

Her husband, she said, has lost his appetite and, seemingly, his interest in life. He has had fainting spells on his job as a shipyard crane operator and cannot accept their son's death or even talk about it.

She has coped better, she said, by visiting a psychiatrist and clinging to the palpable memories that pervade her son's untouched second floor bedroom.

"I'm not ready to bury Albert," she said, clutching in her palm the St. Anthony's medallion he wore the night he was killed. "We have our little chats."

Yesterday, Eastwood, the row house neighborhood just over the Baltimore city border reacted largely along generational lines to the verdict, except for the parents of several teen-agers involved in the events of Jan. 4. e

"We aren't happy with the verdict," said Nicholas Silvestri, whose son participated in the night's events, "This has been very traumatic for all of us. My wife, especially, has a difficult time lately dealing with it. She's been crying a lot. She breaks out a lot for no reason at all. We just want the neighborhood to get back to when it was a nice, people neighborhood. Our kids are not bad kids. They're normal kids."

The jurors, however, said they were unconvinced by the youths' testimony. The panel's discussions, according to jurors Marshall and Betty S. Meszaros, focused on James Willey's version of what happened in the moments before he was shot.

Willey, Marshall recalled, "said he didn't know if he it (Welzant). Well, if he didn't know, how am I supposed to know?"

The jurors discussed the evidence for four hours before taking their first vote, Meszaros said. It then became apparent that Carolyn Holt, a 32-year-old social security claims examiner, wanted to convict Welzant of assault. She argued her point for another six hours before agreeing to acquit, Meszaros said.

Holt would comment on the case.