A Wheaton couple were awakened early Sunday by their 4-year-old daughter screaming in her bedroom. The girl's mother rushed in and found a stranger -- naked and apparently drunk -- lying on top of the girl, Montgomery County police said yesterday.

The mother screamed, the father rushed into the room, and Vicente Perez-Hernandez, 40, climbed off the girl and sat on the edge of the bed, according to police.

The couple called for help, and the girl's father stood watch over Perez-Hernandez, who is 5-foot-4 and weighs 140 pounds, until police arrived about 2 a.m.

Authorities said Perez-Hernandez apparently let himself into the second-floor apartment while the family was sleeping. The victim's father told police he might have inadvertently left the front door unlocked after he came home with his arms filled with groceries.

The family had never before seen Perez-Hernandez, and it is unclear why he decided to enter their apartment, police said.

"Nobody knows how he ended up at this place," Detective Mike Parker said yesterday. "He's a total, complete stranger."

Though the assailant partially disrobed the girl, she was not physically harmed, according to police. They said Perez-Hernandez's clothes were strewn in the room and his breath smelled of alcohol.

The Washington Post generally does not publish the names of victims of sex crimes or other information, such as relatives' names, that could identify a victim.

Perez-Hernandez, who police said recently arrived in the United States from Guatemala, was charged with attempted burglary and attempted rape. He was jailed yesterday in lieu of a $1 million bond. "Even though the bail is extremely high, I don't find it to be excessive at all," said Montgomery District Court Judge Barry A. Hamilton, who grimaced as Assistant State's Attorney Kathy Knight described the allegations at a bond hearing.

Knight said authorities yesterday had not determined Perez-Hernandez's immigration status.

Lohemi Vasquez, Perez-Hernandez's sister-in-law, said he arrived in the United States about three weeks ago. He was living with his brother in an apartment less than a half-mile from the victim's apartment.

Staff researcher Meg Smith contributed to this report.

Vicente Perez- Hernandez, 40, is charged with attempted rape.