With wearing masks in public becoming compulsory to prevent the spread of Covid-19, criminals are also utilising the situation making it difficult for the law enforcers to identify them through CCTV footage.

"Perpetrators often change their tactics, depending on the situation," said Krishna Pada Roy, additional commissioner (Crime) of Dhaka Metropolitan Police.

He said the numbers of incidents where criminals used masks are not too high yet. "We have already detected and arrested those involved in crimes using masks as a shield at the primary stages of the pandemic," he told The Daily Star recently.

The additional commissioner said to stop crime, they are conducting field-level investigation and gleaning information from previously-arrested criminals.

Masked criminals, however, continue to commit crimes across the capital.

Last month, three people shot jhut (garment waste) trader Sattar Matubbor in Rupnagar while he was walking in front of his house.

Sattar is now undergoing treatment at Dhaka Medical College Hospital.

Abul Bashar Mohammad Asaduzzaman, inspector (investigation) of Rupnagar Police Station, said they are investigating into the case but were yet to get any clue. Police could not trace the attackers as they were wearing masks, he said.

On May 3, criminals looted medical products worth around Tk 3 lakh, breaking the shutter of a medical shop at Mirhazaribagh of Jatrabari.

Mazharul Islam, officer-in-charge of Jatrabari Police Station, told The Daily Star that they have got CCTV footage of the incidents. "They used a private car during the robbery. But, all of them were wearing masks and the car had no number plate. For this reason, we failed to solve the case even though over a month has passed," he said.

Mazhar said a few incidents have been reported during the last three months but it gets quite difficult for them to trace criminals as they use masks.

"For this reason, we have once again activated our sources and are trying to detect criminals through contacts and field investigations," added the OC.

According to sources, at least a dozen of robbery incidents took place in the capital in the last one and a half months, which are yet to be detected or solved.

On May 16, two muggers riding on a bike looted Tk 1.82 lakh from a passenger on a rickshaw at Bakshi Bazar of Chawk Bazar. Five days later, criminals' looted valuables from a storehouse at Begum Bazar.

OC Moudud Hawlader of Chawk Bazar Police Station said they have the CCTV footage of these incidents but the criminals were wearing masks, and could not be detected. "We are trying to identify them through our sources," he added.

Moudud further said they have increased patrolling so that these kinds of incidents do not take place.

Meanwhile, the number of crime incidents, which declined in April, compared to March, increased in May, especially incidents of murder and theft across the country.

According to sources in Police Headquarters, around 25 robberies, 275 murders, 490 rape incidents, 1,005 cases of repression on women, 210 cases of repression on children, 38 abduction and 558 incidents of theft took place in March. But in April, the incidents saw a sharp decline with 10 robberies, 275 murders, 335 incidents of rape, 465 cases of repression on women, 125 cases of repression on children, eight abduction and 290 incidents of theft taking place.

However in May, there were around 12 incidents of robberies, 360 murders, 355 incidents of rape, 670 cases of repression on women, 140 cases of repression on children and 390 incidents of theft.

Mahbub Alam, joint commissioner of the Detective Branch of DMP, said, "Some incidents are taking place but police are looking into those and taking action."

Md Omar Faruk, associate professor of Criminology and Police Science of Mawlana Bhashani Science and Technology University, said crime incidents declined in March as people were in fear of the virus but it started rising again as their movement increased after April.

People's income also shrank due to the pandemic, he said. Faruk said the government should take steps in this regard. "If effective measures are not taken immediately, crime rates will continue to increase," he added.