A man who was fatally shot while walking his dog in Northwest Washington was killed in a "face-to-face" encounter with his assailant, police said yesterday.

Investigators said they had no motive or suspect in the slaying of Gregory C. Shipe, 34, a financial analyst for a large public relations firm downtown. He was shot in the face about 10:40 p.m. Saturday in a crime that one top D.C. police official yesterday called "bizarre."

"There was no rhyme or reason for this," said Capt. C.V. Morris, supervisor of the department's violent crimes division. "The motive in this is a mystery. . . . This was a face-to-face confrontation. Of what type? We don't know."

Shipe was walking his dog, Otis, in the 1700 block of Irving Street NW, in the city's Mount Pleasant section, when he was approached by at least one person, police said. He was shot in the face at close range and died at the scene. His dog, a 50-pound mixed-breed, wandered back to Shipe's residence in a nearby apartment complex, where he was discovered by neighbors.

Although none of Shipe's possessions, including his wallet, was missing, investigators speculated that he most likely was the victim of a botched robbery, authorities said. Police and neighbors said several robberies have taken place in the area recently.

Shipe worked as a financial analyst in the Washington office of Ogilvy Public Relations. He started in May on a temporary basis but soon was hired full time, said Robert Mathias, managing director of the 100-employee office.

Mathias said employees were devastated by the death of a charming colleague who quickly solved problems.

"There was always just good cheer about him," Mathias said. "He was just a very positive part of our work culture. . . . Nobody deserves this. But of all the people who don't deserve this, Greg is at the front of that line."

Shipe grew up in Waynesburg, Pa., a small community about 50 miles from Pittsburgh. He graduated from the University of Kentucky with a bachelor's degree in business administration.

From 1998 through 2002, he lived in Washington and worked as an analyst for Lockheed Martin Corp. and as a consultant for Booz Allen Hamilton, according to a resume supplied by Ogilvy.

He attended Owen Graduate School of Management at Vanderbilt University and graduated with an MBA in finance last year.

Business school classmates said that Shipe was a hard-working student and that he co-chaired the gift committee for his 2004 class. The committee raised $118,000 to help refurbish a classroom, shattering fundraising records for class gifts, said Clint Liebenberg, a friend and the former class president.

"He was selfless," Liebenberg said. "He worked really tirelessly on his own time to make sure he achieved his own goals. . . . He was just friendly with everybody and had a really positive outlook on life."

Shipe had been living with friends in Columbia Heights until several weeks ago, when he moved into an apartment in the 1600 block of Kenyon Street NW, police and friends said.

A bouquet of red and yellow flowers and two cards were outside Shipe's apartment door yesterday. Vanessa White, a neighbor, gave Shipe the keys to his apartment about three weeks ago and said she had been looking forward to getting to know him better.

"It's tragic. He was such a nice guy," White said. "The fact that you saw someone in the hall one day and then the next day they are murdered a block away, it shakes you up. . . . When we found out, we kept on saying that could have been any of us. We're always out walking around that late or later. This will make all of us be much more cautious about returning to the building after dark."

Keisha Barkley, who lives in the 1700 block of Irving, said she was surprised to hear that someone was killed in her neighborhood.

"There's no drug activity. It's just a pretty quiet, nice residential neighborhood," she said. "There have been a couple of robberies, car break-ins, that's the only thing that happens in this neighborhood."

A candlelight vigil for Shipe is scheduled to begin at 8:45 tonight outside the Mount Pleasant Neighborhood Library at 3160 16th St. NW. Mourners will walk to the 1700 block of Irving Street NW, where Shipe was slain, organizers said.

Police urged anyone with information to call 202-727-9099. They are offering a reward of up to $25,000 for information leading to the arrest and conviction of a suspect.

A bouquet was placed on Irving Street NW near where Shipe was shot. Flowers and cards also were left at his Mount Pleasant apartment. Gregory C. Shipe was killed Saturday night while walking his dog. Police said the motive is unknown.