Ryan T. Stowers, a Navy seaman, flew to Maryland from California on Wednesday, hoping to get on with his life.

He had tried community college and had thought about joining the Air Force. Instead, he joined the Navy in March. Then, after boot camp, he injured one of his knees and underwent surgery in September at National Naval Medical Center in Bethesda. After recuperating in California, he returned to Bethesda last week, getting ready to return to duty.

"He was in such a hurry to get out there," said his mother, Tricia Stowers, in a telephone interview from her home in Redding, Calif. He wanted to settle into Navy life.

But that fell apart in a few moments Thursday night.

Stowers, 20, was driving on Rockville Pike shortly before 8:30 p.m. when he and another motorist, Arthur L. Lloyd, 53, a deputy U.S. marshal, had an altercation in traffic, Montgomery County police said. The two pulled into the parking lot of Mid-Pike Plaza in Rockville, where their shouting match turned into a fistfight, police said.

Witnesses said Stowers got back in his car and was attempting to drive away when Lloyd fired repeatedly at the vehicle, killing Stowers. Police said they were interviewing witnesses yesterday and had not decided whether to file charges against Lloyd.

Lloyd, a deputy for 28 years, could not be located for comment yesterday. His wife, Wanda Lloyd, referred questions to her husband's attorney, Lawrence Berger, who declined to comment on the case.

"The guy shot my son in the back," Todd Stowers said in a telephone interview from California. He said he is worried that the incident will not be fully investigated because it involved a federal law enforcement officer. "This is my 20-year-old kid," the father said.

Ryan Stowers grew up playing baseball, soccer and basketball and swimming, his mother said. He and his younger brother, Matt Stowers, were best friends, always together, said Tricia Stowers. While his sister, Tristan Stowers, knew she wanted to be a teacher, and the family expects Matt Stowers, a recent high school graduate, to become a businessman, Ryan Stowers was still figuring out where his life was going, his mother said.

Tall and thin, Stowers played shortstop for his high school baseball team and point guard for the basketball team. His main interest was sports, his mother said.

And "every time I turned around," Tricia Stowers said, "he was on the phone with some girl."

Stowers went to community college and worked at a video store. He considered joining the Air Force to become a military police officer but decided that would take too long, his mother said. So he enlisted in the Navy and signed up for a cooking program.

Stowers joined the Navy on March 1, according to Lt. Cmdr. Chito Peppler, a spokesman for National Naval Medical Center. After basic training, Stowers was assigned to the USS Detroit, a combat support ship based in New Jersey. But he never got to go to sea. After he hurt a knee playing basketball, he was sent to Bethesda for surgery.

He told his family that in boot camp he went to religious services -- and they teased him, telling him he went to church just to get some sleep in a place where no one was yelling at him. But, his mother said, "I think he was kind of looking for something there, too, not quite knowing what it was yet."

Stowers called home every day and worried that his sister's baby daughter would not remember him when he came back. He and his girlfriend, a Maryland college sophomore, sent his 17-month-old niece a rubber duck wearing a Navy hat.

In Maryland, where he drove a 1997 Chevrolet Camaro, he got a ticket for speeding and one for driving the wrong way on a one-way street. After his surgery at the end of September, he returned to Redding for a month. After sailors have medical treatment at the hospital, they usually are assigned to work there for a time.

Stowers was to have begun working there Friday, his mother said.

His sister wrote in an e-mail message that she hopes that witnesses to the shooting will help police learn the truth about what happened to her brother.

"He was just looking for his place," his mother said.

Staff writer Clarence Williams and staff researcher Bobbye Pratt contributed to this report.

Ryan T. Stowers was in an "altercation" on Rockville Pike, police said.A Montgomery police investigator, left, surveys the scene of an incident Thursday at the Mid-Pike Plaza in Rockville, where Ryan T. Stowers, above, was shot to death after being involved in an altercation with another motorist on Rockville Pike, police said. Stowers was attempting to drive away when he was shot, witnesses told police.