Four persons were slain -- two by stabbing -- in separate incidents in the District between Saturday night and early Monday morning. D.C. police made an arrest in each stabbing.

The killings raise the District's homicide count this year to 465. There were 416 homicides reported in the District at this time last year.

Police released the identities of three victims and were withholding the name of the fourth until relatives are notified.

In the first killing, on Saturday night, a police spokesman said officers responded to a report of a fight at a home in the 1700 block of H Street NE.

There, officers found that Vincent Parker, 35, whose address was given as a post office box in Culpeper, Va., had been stabbed in the lower back. He was taken to D.C. General Hospital, where he died at 10:12 p.m.

Iris Williams, 33, of the H Street address, was charged with second-degree murder.

In the second stabbing, police said a Northwest Washington man was killed early yesterday morning by his roommate in a house in the 700 block of Fairmont Street NW.

Eric Nolan, 22, was taken to Washington Hospital Center with multiple stab wounds and died at 2:27 a.m., police said.

David O. Torres, 27, was charged with second-degree murder.

A neighbor said that the house was owned by Torres' mother, who also lived there.

Yesterday, police identified the man shot dead outside an apartment building in the 6800 block of Georgia Avenue NW early Sunday morning as Khan A. Daley, 18, of the 6000 block of Georgia Avenue NW.

Daley was shot along with an unidentified man.

Both were taken to Washington Hospital Center, where Daley died.

The wounded man was treated there and released.

The unidentified slaying victim was shot at 8:50 p.m. Saturday night in a home in the 3000 block of South Dakota Avenue NE, police said.

He was taken to Washington Hospital Center and died there at 6:50 a.m. Sunday. No other details were disclosed.