After a night out with friends to celebrate Grand Prix weekend, 20-year-old Sheila Ansah thought taking a taxi would be the safest way to get home.

But when the taxi driver arrived at her Saint-Laurent home, he got out and walked around the car to open the door for her. When she got out, he grabbed her, lifted her off her feet and set her down outside her building.

He then pushed her against a wooden fence and began to grope her upper thighs and breathe heavily.

Ansah said that when he picked her up she felt "really overwhelmed" and didn't know how to respond. But as soon as he began touching her, alarm bells went off in her head.

"[When] he started touching me I thought, 'whoa Sheila, this isn't normal, this never happens to you, I don't understand why you're letting this happen,'" she told CBC News.

"The thing that really scared me was the way he was heavy breathing. It felt like he was getting more aggressive and wanted to do something else if I let him. But I wasn't going to let him do that to me."

Ansah managed to push him off and get inside her building.

"I ran upstairs and didn't look back," she said. "I didn't want anything to do with him."

According to Montreal's Taxi Bureau, 60 per cent of taxi drivers have now undergone a criminal record check. (CBC News)

Diamond Taxi management unaware of incident

The next day Ansah called Diamond Taxi to report the incident. She was told that because she hailed the cab off the street and didn't know the license plate number, she didn't have enough information to identify the driver.

She was told to contact the general manager if she learned of any new information, but was not asked to file a formal complaint.

Raffi Artinian, deputy general manager of Diamond Taxi, said he did not receive a report of Ansah's case.

"We have not had any assault cases reported to us as far as I can remember," he wrote in an email to CBC News.

Artinian said he will be investigating how the call was handled, as all serious complaints should be reported to management and dealt with immediately.​

'Every case is one case too many'

As recently as 2014, Montreal was one of the only cities in Canada that didn't require taxi drivers to undergo criminal record checks.

That policy was changed after a series of CBC News investigations into sexual assaults in Montreal taxis. Since January 2015, all Montreal taxi drivers obtaining or renewing a taxi license have been required to undergo a criminal record check.

Marie-Helene Giguere, a spokesperson for Montreal's Taxi Bureau, said that "every case is one case too many."

Since the implementation of the new policy, 60 per cent of Montreal taxi drivers have undergone a criminal record check. The bureau said that by the end of 2016, 100 per cent of taxi drivers will have been verified.

Numbers obtained from the bureau indicate that 126 drivers, roughly 3 per cent of those who have been screened, failed to pass the criminal record check.

Ninety-eight of those drivers asked for the decision to be reviewed, and only 11 were eventually unable to obtain or renew their license.

The bureau has also outlined a plan to mount cameras in all taxis, which are scheduled to be installed later this year.

Police encourage all victims to report

Ansah said that she is still unsure whether she'll report her case to the police. She feels that she doesn't have enough information to identify her attacker.

Carolyn Cournoyer, a commander and community liaison officer with the Montreal police, said that victims of violent assaults often hesitate to come forward, especially when there are no witnesses to back them up.

I'm pretty sure this happens to a lot of women. And no one speaks out about it because they think no one's going to do something about it. - Sheila Ansah

"When a victim is alone in their experience, they may feel less confident to report the infraction because they worry that they won't be believed," Cournoyer said.

"But just because there are no witnesses to a crime does not mean that we can't open an investigation."

Cournoyer added that even basic facts about an event can help the police launch an investigation and ultimately identify an offender.

There were 33 recorded sexual assaults in Montreal taxis in 2013, and 27 cases in 2014, according to data compiled by Montreal police.

Data from 2015 has not yet been compiled, and Montreal police say it's still too early to tell whether the new background checks policy has had any impact.

Carolyn Cournoyer, a commander and community liaison officer with the Montreal Police, said she encourages all victims of assault to come forward, even if they feel that they are unable to identify their attacker. (CBC News)

'No one speaks out'

Ansah said she is speaking out because she believes many women hesitate to come forward out of fear they won't be believed.

"I'm pretty sure this happens to a lot of women," she said. "And no one speaks out about it because they think no one's going to do something about it."

She hopes her story will encourage other women to be vigilant while riding in taxis alone.