MIAMI -- A woman was raped after her sister's house keys were stolen in a carjacking nearly a month ago, police said.

Police said the victims of crimes often try to put the ugly situation behind them as soon as possible. In this case, police said when their house keys were stolen in a carjacking, the victims did not move fast enough to have their locks changed. Police said this led to the rape of the carjacking victim's sister.

The Story In Pictures: Stolen Keys Lead To Rape

"We need citizens on patrol along with police officers and making the citizens aware of some of the incidents going on," Miami police officer Vernell Reynolds said.

In a press release, police said the 21-year-old rape victim's sister and her boyfriend were robbed on Feb. 7 near 19th Avenue and Northwest 49th Street. Police said the suspect took their candy red 1988 Oldsmobile along with a purse containing the family house keys.

Police said the house locks were never changed.

"When he pulled off the robbery, he had all the ingredients he needed to pull off the next crime," Lt. Bill Schwartz, of the Miami Police Department, said.

Three weeks after the original carjacking, police said the suspect struck again at 6 a.m. on Feb. 27 near Northwest 46th Street and 17th Avenue.

The robbery victim's sister was surprised in their home and raped at gunpoint in front of her two small children, police said.

Police said the suspect fit the same description as the carjacker.

The suspect left the victim's sister's house keys and car keys behind, but the car is still missing, officials said.

"If you are the victim of a crime, look ahead because the dirt bag is going to look ahead. If he has your keys and your address, you will be victimized. You have to assume that. Change your locks," Schwartz said.

Police immediately beefed up patrols and community leaders asked residents to lend a hand.

"And make those phone calls when they see something they think is suspicious," David Chiverton, of the Miami Police Department, said.

The suspect is described as a black man in his early 20s, about 5 feet 7 inches, 135 pounds, with four upper gold teeth, a thick beard with no moustache and a tattoo on his right arm. The man was last seen riding a gold mountain-type bicycle.

Police said the suspect is dangerous because he told the rape victim not to call police and said he liked to kill people.

Anyone with information is asked to call Crimestoppers at (305) 471-TIPS.