Four males have been arrested in Richmond, California, during investigations over the alleged gang rape of a lesbian.

31 year old Humberto Hernandez Salvador was arrested on Wednesday at his home in Richmond.

He is currently being held without bail for kidnapping, carjacking and gang rape, as well as violating probabtion.

A 15 year old boy from Richmond, who has not been named, was also arrested on Wednesday on suspicion of sexual assault, kidnapping and robbery.

A third suspect, a 16 year old boy from Hercules, turned himself in to police on Wednesday night.

This suspect was accompanied by his family, SFGate reports.

A final suspect, Josue Gonzalez, was arrested on Thursday. The 21 year old turned himself in after a $1 million warrant was issued for his arrest.

Gonzalez was accompanied to the police station by his girlfriend, stepfather and mother, who had urged him to go to police after seeing reports of the attack.

Richmond Police Lieutenant Mark Gagan told the Associated Press:

“The crime had an immediate effect on our community.

“Locally people were very afraid to know that these people were out there.”

After the attack local people distributed leaflets asking for witnesses and held vigils for the victim.

The 28 year old woman, who cannot be named, was attacked on 13th December.

The suspects allegedly attacked as she got out of her car.

According to police, the suspects knew the victim was a lesbian, due to a rainbow gay pride stick on her vehicle, and made comments about her sexuality.

For this reason, police have classed the assault as a hate crime.

The suspects then allegedly embarked on a 45-minute attack, when they hit the woman with a blunt implement, undressed her and raped her.

On seeing another person approaching, police said, the suspects allegedly put the woman into her car and took her to a derelict apartment building.

Here the victim was raped again, before being left naked outside the building whilst suspects allegedly stole her wallet and car.

The victim is currently recovering, and a non-profit rape crisis centre, Community Violence Solutions, has opened a fund under a pseudonym to help her pay for relocation.