The suspect arrested in the rape of a mentally disabled teen aboard a Metro bus has an extensive criminal history, including charges of sexual assault, authorities said Friday.

Kerry Trotter, 20, of South Los Angeles, was arrested early Friday after the Los Angeles County Sheriff's Department announced that detectives were searching for a man who had boarded a bus and for 10 minutes raped an 18-year-old woman. Trotter is being held on $1 million bail.

Authorities were also investigating whether the bus driver took appropriate action when the rape was reported aboard his bus. A lone witness had tried to get the driver's attention while the assault occurred, according to sheriff's department officials.

The attack happened about 5 p.m. Wednesday after the victim and her attacker boarded Bus Line 217 at La Cienega and Jefferson boulevards, according to the Los Angeles County Sheriff’s Department.

The 10-minute attack occurred at the rear of the bus, deputies said.

After it was over, the rapist got off the bus at Sepulveda Boulevard and Slauson Avenue, the route’s last stop.

The victim, who was said to have the mental capacity of a 10 year old, then told the driver after her assailant left the bus.

"She did not scream or shout out," said Sgt. Dan Scott with the Sheriff's Department. "She was too afraid to do so."

Investigators say that an anonymous tip led them to arrest Trotter, pictured above, after an image of the suspect taken by a surveillance camera on the bus was publicly released.

Deputies located and arrested Trotter at a home in the 1400 Block of West 99th Street.

A search of the home "provided additional evidence to support the allegations," the sheriff's department said in a press release.

Sheriff’s officials said during the rape, an unknown witness, the only other passenger on the bus, attempted to get the bus driver’s attention, a claim that Metro officials took issue with.

"This is a terrible, tragic incident," said Marc Littman, a spokesman with the Los Angeles County Metropolitan Transportation Authority. "But what the operator saw or didn’t see, we don’t know until we see the surveillance video."

The bus driver, Ricky George, was placed on paid administrative leave while detectives investigate his role in reporting the case, Littman said.

Bus drivers are trained to call transit dispatchers when they become aware of a possible crime, Littman said. If a crime is in progress, there is a silent alarm on board that can be tripped, he said.

In 2012, there have been two sexual assaults reported on Los Angeles County buses and one reported at Union Station, Littman said.

Anyone with information about the incident was asked to call the LA County Sheriff’s Department Special Victims Bureau at 866-247-LASD (5877).

The Associated Press contributed to this report.