The ex-boyfriend of a woman killed in her mother’s apartment in New York University faculty housing was charged with her murder yesterday, police officials said.

The suspect, Michael Cordero, 23, was arrested after he attempted to commit suicide by slashing his wrists at about 8 p.m. Tuesday on the roof of an Upper West Side building. He later gave a detailed confession to investigators at the hospital, according to officials.

Mr. Cordero told police he had argued with the victim, Boitumelo McCallum, on Friday in the apartment of her mother, Teboho Moja, a professor at NYU who was working in South Africa for the summer. He then described in detail how he had murdered her, police officials said.

“His account is consistent to the injuries to her body,” a police spokesman, Deputy Commissioner Paul Browne, said. “He went into considerable detail.”

The medical examiner said yesterday that McCallum died after she was strangled and smothered with a towel, and police have said she had a fractured nose.

Family and friends of McCallum have described her relationship with Mr. Cordero as troubled and said she had been trying to break it off for months.

McCallum’s body, wrapped in a sheet behind her bed, was found on Sunday by subletters sharing the apartment. Her room was locked from the inside.

Family members of the victim are “just happy he’s caught,” Patricia Maguire, the mother of McCallum’s stepmother, said yesterday. Ms. Maguire, the victim’s younger brother, and her father and stepmother, Robert McCallum and Cindy Maguire, both professors at NYU, last saw her at a goodbye dinner on Wednesday as they prepared to travel to South Africa the next day.

After the dinner, McCallum had a party, which Mr. Cordero did not attend, police said. Friends last saw her alive on Thursday, police said.

McCallum’s family spent Tuesday trying to fly back to the city from South Africa. They are said to be planning to take her body back to South Africa, where she was born, for burial.

It was unclear where Mr. Cordero had been hiding since Sunday, when McCallum’s body was found and police began searching for him to question him about her death. On Tuesday night, Mr. Cordero attempted to kill himself on the roof of a building in the Amsterdam Houses near Lincoln Center, police said. After cutting his wrists, Mr. Cordero fled the building, pursued by members of his family, police said.

Passers-by, believing they were seeing a police chase, called 911, and police responded to a nearby Western Beef grocery store, where they found Mr. Cordero with knife wounds to his wrists.

Mr. Cordero was being held at Roosevelt Hospital yesterday on a 72-hour suicide watch. Police said they were planning to transfer him to Bellevue Hospital and that upon his release he would be arraigned on a charge of second-degree murder.

At the hospital, police said Mr. Cordero told nurses, “I tried to kill myself because I killed my girlfriend.”

In his interview with investigators, Mr. Cordero described the murder in matter-of-fact detail but also seemed remorseful, police sources said.