Wedding guests leaving a reception at a monastery in Northeast Washington were attacked Saturday night by robbers who beat three of them with a pistol and then shot a fourth to death, D.C. police said.

The man, 57, was shot once in the chest near 14th and Quincy streets shortly before 11 p.m., police said. He had just given his money to an armed assailant and an accomplice, said Capt. C.V. Morris, head of the violent crimes unit.

Police would not identify the man, who was from the Philadelphia area, citing a request from the victim's relatives that they be allowed to notify other family members first.

About five hours after the killing, a Catholic University student was shot and wounded in the same neighborhood by one of three men who had tried to crash a party, according to police and another student. Police said they were trying to determine whether the shootings were related.

Morris said that the attack on the wedding guests occurred as the shooting victim and three relatives had just left a reception at St. Francis Hall at the Franciscan Monastery. They were accosted by at least two assailants who demanded money, Morris said. The guests, two men and two women, weren't given much time to comply before one assailant began pistol-whipping them on the face and head.

"He immediately started striking the women and one of the males," Morris said.

The robbery turned fatal, Morris said, after the 57-year-old man threw his money at one of the assailants. Police believe that this sudden action might have prompted the gunfire.

Other wedding guests said at least one of the women returned to St. Francis Hall, her head bloodied. One man, who would not give his name but said he had administered first aid, said the wounded man was conscious and kept asking why he had been shot even though he had given the assailants his money.

Stunned guests left the reception hall to find that police had cordoned off the area with tape while investigators surveyed the scene.

Police officials had only a vague description of the assailants, who fled on foot. Police searched the area in a helicopter and patrol cars early yesterday morning, and investigators spent yesterday continuing to canvass the area for witnesses. No suspects had been apprehended as of late last night.

The robbery occurred along a lighted but isolated hillside block in the Brookland neighborhood.

The shooting victim was taken to Washington Hospital Center, where he was pronounced dead at 12:20 a.m. yesterday, authorities said. The other victims were also taken to Washington Hospital Center, where they were treated for head and facial wounds and released, Morris said.

The assailants escaped with money, wallets and purses from the victims. Anyone with information is asked to call police at 202-727-9099.

In the later incident, a 21-year-old Catholic University student was shot in the abdomen in the 1000 block of Newton Street NE. Police said he was shot by one of three people who had entered a car after being asked to leave a party in the Newton Street block. The student was treated at Washington Hospital Center and released. Police said they found similarities in the descriptions of the assailants in the two incidents.

In the second incident, the car in which the assailants fled was described as a dark-colored Honda or Acura.

Staff writers Allan Lengel and Martin Weil contributed to this report.