Beijing police officer Zou spent his 31st birthday doing what he enjoys most－outwitting a pickpocket who thought he was too smart to be caught.

"I felt a sense of achievement that I'd made a safer environment for the city's residents," said Zou, whose full name can't be given by the Beijing Public Security Bureau as it may help pickpockets identify him.

Zou took his team to Liyuan, Tongzhou district, in early September after several residents reported they had been robbed on buses.

After analyzing reports of the thefts, he noticed similar techniques were used even though they happened on different buses.

"The suspect might be a repeat offender with experience in knowing when he's under surveillance," Zou warned his team.

He ordered his team members to stake out buses and bus stations where the suspect had struck. But five days went by without any arrest.

While the other police officers became impatient and a little disillusioned, Zou did not give up. "A successful capture sometimes takes time, and what we needed was patience," he said.

Persistence paid off, and at one of the bus stations under surveillance a 60-year-old pickpocket was arrested on Sept 12. To Zou's surprise, he had detained the same man for theft a year earlier in Chaoyang district.

After he graduated from the Criminal Investigation Police University of China, Zou began his career chasing pickpockets in August 2012.

To date, Zou and his colleagues have smashed 34 pickpocketing gangs and detained 620 suspects for theft, according to statistics provided by the bureau.

More than 490 mobile phones have been retrieved as well as 140,000 yuan ($19,909) in cash, it said.

Since January, Zou's team has caught 82 thieves and broken up eight gangs, making it one of the top anti-pickpocketing teams in Beijing.

The bureau attributed much of the team's success to Zou's years of research on how to efficiently combat thieves.

"I like to apply investigative techniques, or means, in the crackdowns against pickpockets to improve the detection of offenders," Zou said.

After he realized pickpocket gangs in Beijing had moved their operations from six downtown districts, he took his team to markets and transport hubs on the city's outskirts, including Shunyi, Tongzhou and Daxing districts.

"Our actions must follow the thefts. Where the pickpockets frequently appear is where we will go," Zou said.

In July, Zou's team caught five people suspected of stealing gold necklaces at an agricultural market in Tongzhou. They subsequently launched a crackdown in other markets in the district as well as in Daxing and Fangshan.

Although Zou has spent eight years solving thefts across the city, he remains passionate about his work and said he is a newcomer with many things still to learn.

"Compared with police officers specializing in solving big criminal cases my job seems easy and not exciting, but I am closer to residents and their everyday lives," Zou said. "Fighting pickpockets and helping people get property back keeps the city orderly and protects public security. That's the most significant thing about my job and I'll continue shouldering the responsibility."