She never felt truly safe living in California in the United States.
Her car had been broken into and there was even a shooting at the school where she was a teacher.
But it was Ms Jennifer Jacoby's two children who led her to take up krav maga, a little-known form of self-defence used by the Israeli military.
Now living in Singapore, the 40-year-old is on her way to becoming an instructor in the self-defence system.
Ms Jacoby and her two children, aged 11 and 13, moved here in 2009 when her husband was posted here.
Speaking of her life in the US, she said: "There was much more potential for being a victim and there isn't the sense of security that Singapore gives."
Tired of being bullied, her children enrolled for krav maga lessons.
She said: "My children started learning krav maga to defend themselves and they quickly became more confident.
"They were able to stand up for themselves as they had more tools for self-defence," she added, saying that they even stood up for a disabled schoolmate who was being bullied.
After seeing this change in them, she decided to go for the self-defence system.
Krav maga is a street-fighting system used by the Isreali military. It is gaining popularity in Singapore.
Ms Jacoby has been doing krav maga for five years.
"In dangerous situations, there's a switch in my head that I flip. I know when to de-escalate or escalate the situation.
Another student, television producer Idzwan Othman, 36, started learning krav maga after being assaulted one day.
His job at a production house often means going to dangerous places around the world like conflict zones. Yet it was an incident in Singapore four years ago that changed his mind.
He had got into a scuffle with another man after a drinking session. Mr Idzwan was hit in the face and had a cut lip and several bruises.
He said: "I didn't want a system like mixed martial arts (MMA), which was not for self-defence but for the ring. Krav maga offers a complete package.
"The more I learn, the more I want to avoid fights as the potential injuries are scary. If I have to defend myself, I am confident I can handle myself a lot better," he said.
One reason krav maga is increasingly popular is because it is beginner-friendly, said Mr Sascha Soliano, 39, director of Military Krav Maga under the International Krav Maga Federation (IKMF).
He told The New Paper: "A person who has already learnt martial arts will do things in a set way, with fixed drills. It is harder for such a person to start from scratch."
Krav maga is Hebrew for "contact combat", said Mr Soliano, who is head instructor at the Krav Maga Singapore school .
LIKE REAL LIFE
Based on real-life situations such as armed robberies, it involves techniques deemed illegal in martial arts competitions such as eye gouges, groin strikes and even throat jabs to defend oneself against attackers.
Students routinely train with rubber knives, plastic pistols and padded sticks to better simulate conditions on the street.
Mr Soliano said that krav maga is based on a person's natural reflex to a confrontation..
"This is not a martial art, not a sport. There are no kata (a fixed set of drills used in martial arts) and no rules.
"It is about what happens on the street. It is a practical self defence system for the general layperson," he said.
Mr Edwin Peng, 33, director of Krav Maga Global Singapore, said: "We train students to deal with situations where they are surrounded by multiple armed attackers.
"They react to problems and get away quickly without any fanciful stuff. The minimum effort for the maximum results," he said.
Sharp rise in krav maga student numbers
More are signing up for self-defence classes and enrolment rates at schools have been growing in the last five years.
Krav Maga Academy opened in 2006 with between five and 10 students. It now sees an average of 20 to 25 students each night.
Krav Maga Culture, meanwhile, had only one or two students a class in 2012. Its class size now averages 20.
Another self-defence school, Kapap Academy Singapore, offers a curriculum that combines moves from ju-jitsu, catch wrestling, taekwon-do and krav maga.
Ms Qin Yunquan, 24, chief instructor of women and youth at Kapap Academy, said interest has spiked from 50 to 60 students in its first year to more than 3,000 now.
"We offer an integrated curriculum which is very popular with ladies. Over 90 per cent of our students are women."
She added: "Our students are taught never to go strength for strength with aggressors but to rely on techniques instead."
Other martial arts which do not cater specifically to self-defence are also seeing more takers.
Mr Darren de Silva, 41, head trainer of Fight G MMA Academy, which provides courses in muay thai, ju-jitsu and MMA, has seen a 40 per cent increase in adult membership.
This article was first published on June 24, 2014.
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