The first victim heard a knock on her door just before 2 p.m. She opened it, and the man pushed his way inside her new apartment in Northeast Washington.

According to court papers filed by police Monday, the man knocked his victim to the floor, tried to sexually assault her and then stabbed her, punched her and kicked her in the face, head, back and legs. He then left her, bloodied and unconscious, lying on the floor.

On Friday, a week after the first assault, police said in the court papers that the same man walked into an all-female Howard University dormitory and forced his way into a woman’s room. He slapped her, pushed her onto her stomach, pulled out a brass-knuckle type weapon with a blade on the end and began sexually assaulting her. When she yelled for him to stop, the man grabbed a piece of paper, wrote the name “Marco” and a phone number and left it.

Police used the name and cellphone number, along with surveillance video from the first assault, in the 2300 block of Washington Place NE, and on Saturday arrested DeMarco Myles. Myles, 19, of Northwest is being held in the D.C. jail.

According to the documents, Myles told detectives that he stabbed the woman in Northeast after he tried to rob her and she resisted. “I didn’t mean to kill anyone. I was just going to take what she had,” he said, according to the charging documents. The first victim was in critical condition in a local hospital but survived the attack.

He also told police that the sex with the Howard student was consensual and that he never unclipped the knife from his belt.

At a hearing Saturday in D.C. Superior Court, Myles was ordered held until his next appearance, on Nov. 13. Prosecutors charged Myles with assault with intent to kill, first-degree sexual abuse and assault with intent to commit first-degree sexual abuse.

Meanwhile, D.C. police are trying to determine whether the unusual, brass-knuckle style knife was used in any other attacks.

Witnesses in the dormitory, called the Bethune Annex, a sprawling building on Fourth Street NW that houses up to 550 female students, told police that a man fitting Myles’s description had been hanging around the dorm. He tried to start up casual conversation with women, but always left when he was told, the witnesses said.

On Howard’s campus Monday, students said security at the dormitory had been lax before the attack.

“Before, they didn’t even check IDs,” said Houston native Kendahl Rose, 17, who lives in the dorm. “Today was the first time they checked. They made me show my card and checked it.”

Rose said university leaders called an emergency meeting, but she complained that officials were unable to tell the attendees how the attacker got into the dorm.

Nyasha Simmons, a freshman biology mayor from New York, said students on campus were “very worried” about safety on campus, but added she was not surprised someone was able to get into the dorm. Students regularly find ways to sneak their friends in, she said.

Kerry-Ann Hamilton, a Howard spokeswoman, said the front desk has long been staffed 24 hours a day. She added that additional, round-the-clock guards have been added since the attack and will be gradually rolled out to other dorms.

Hamilton added that security cameras record all entry and exit points. She said there were no university police reports from students in the dorm about seeing a man fitting Myles’s description before Friday’s attack.

“Safety of our campus community is paramount,” Hamilton said.

The mother of the student victim flew to Washington over the weekend and said she planned to meet with D.C. police and prosecutors Wednesday. “I don’t know anything more than what my daughter told me,” she said.

The mother, whom The Washington is not naming to shield the identity of the victim, said she spoke with Howard officials Monday. “They’re working on the issue,” the mother said. “They’re trying to figure out how it happened so it doesn’t occur again.” She said that so far she is satisfied that the university is doing what it can.