A 17-year-old Texas girl and two underage accomplices are accused of staging a robbery and subsequent carjacking in a bid for cash, according to investigators.

Susan Marie Mize, of Spring, is charged with aggravated felony robbery, according to the Montgomery County Sheriff's Office. The two alleged accomplices, ages 16 and 15, are also being charged in the case.

Lt. Scott Spencer, a spokesman for the Sheriff's Office, said in a news release Monday that deputies were called to a grocery store near Spring on Friday because two teens had reported to Harris County deputies that they'd been robbed in Montgomery County.

The responding deputies learned that their Harris County counterparts were called to two separate homes where Mize and her friend, whose name is being withheld because he is a victim of a crime, each said they were robbed, Spencer said.

Investigators learned that Mize asked her male friend if he wanted to earn $150 by driving a couple of her friends to Houston, Spencer said. He agreed, and the pair drove to a park in Montgomery County to pick up Mize’s friends.

They met with the 16-year-old boy and, while awaiting their second alleged passenger, the 15-year-old boy, wearing a mask, approached the driver’s side door of the male victim’s car and brandished what the victim thought was a handgun, according to the news release.

The 15-year-old ordered the victim into the backseat of the car while the older suspect waved a knife around and ordered that the victim be tied up with Mize’s shoelaces, Spencer said.

"The two males then robbed (the victim) of the money in his wallet while striking him numerous times and threatening his life with the knife and gun," Spencer said.

The two male suspects then drove the victim to a store and untied him so he could use the ATM inside to withdraw cash from his account, the news release stated. The 16-year-old went inside with him.

"The suspect and (victim) return to the car, at which time (the victim) is tied back up with Susan's shoelaces," Spencer said. "The suspects then take Susan home, per her request. Susan is dropped off at her residence, but never calls 911 to report what was happening to (the victim)."

The victim convinced the underage boys that he had more cash at home that he would hand over if they drove him there. When the trio arrived at the boy’s home, the suspects waited for him in the car while he went inside.

The victim immediately locked the door and told his parents what happened, Spencer said. His parents called the Harris County Sheriff’s Office.

The boys fled in the victim’s vehicle, which Harris County deputies soon found at another park, along with the teens. Both were taken into custody.

During the subsequent investigation, detectives learned that Mize was part of the plan, Spencer said.

"Susan believed (the victim) was an easy target and the plan was for the males to rob him for the money in his wallet," Spencer said. "Susan advised (that) tying (him) up and taking his car was not her idea or part of the plan."

Investigators who searched the car said they found a kitchen knife and two guns, both of which turned out to be BB guns, the news release stated.