CHANDLER, Ariz. -- A man who has sexually assaulted three girls in Chandler since January appears to be targeting girls from single-parent families, watching his victims closely and attacking after the parent left for work, police said Tuesday.

CONTACT: Chandler Police Department With Any Tips

In the latest incident, Chandler police received a delayed report on Sunday of a sexual assault that occurred Friday.

A 13-year-old girl was sleeping in her bed at 7 a.m. Friday when a masked man came in, woke her up and threatened her with a weapon before sexually assaulting her, according to a Sunday night news release.

The girl's mother had already left for work and the only other person in the house was the girl's younger brother, who was not harmed, Sgt. Rick Griner said in the release.

The girl told police she believes the man is the same man who entered her home at the same time of day about a month ago. At that time, the man told her the neighbor's house was on fire and that she needed to get out of her house. He then told her it was a false alarm before leaving.

Police believe the man who assaulted the girl is the same man responsible for the Jan. 16 and Jan. 31 sexual assaults of two teenage girls.

Those assaults have been linked by physical evidence. Police believe Friday's assault is connected because of the victims' ages, the description of the man, the geographic area of the assaults and the method of operation.

Detectives have released a more detailed description of the man in hopes a friend or family member might recognize him and notify authorities.

In the Jan. 31 attack, police said the suspect wore a brown work coat with an attached tan hood. He wore faded blue jeans and tan work boots that had fresh light blue and white paint drops on them.

Detectives said he also had a cell phone that had an audible ring tone with combined "bells and rings." He wore a black knit cap that he rolled down to become a ski mask.

About three weeks before the March 23rd attack, police said a suspicious vehicle was seen loitering in the area.

It was a white, newer model, Ford F-150 four-door pick-up truck with tinted windows and an unknown Arizona plate.

In the attack, the suspect wore black jeans, a long-sleeved white shirt and white athletic shoes.

Late Tuesday, Chandler police officers were set to canvass the neighborhood to distribute safety information and fliers about the crimes.