The suspect in an alkali attack in south London was convicted of a sex offence in 2018 and was later granted asylum.
Police are looking for Abdul Shakoor Ezedi, 35, who was last seen at a Tesco shop in north London on Wednesday evening.
He was convicted of “sexual assault/exposure” in 2018, before being granted asylum in 2021 or 2022.
The Met Police have issued an image of him showing facial injuries.
The image of Ezedi was released on Thursday – showing “significant injuries” to his right eye. It was taken at a Tesco Express shop on Caledonian Road, north London, at 20:48 GMT on Wednesday.
Police have warned people to call 999 if they see him.
BBC News understands that Ezedi arrived in the UK by lorry in 2016.
His sentence for the sexual offence, passed down at Newcastle Crown Court, included an unpaid work order.
Once that was completed in 2020, Ezedi was discharged from probation supervision.
A mother and daughter hurt by the corrosive substance could have suffered “life-changing” injuries in Wednesday’s attack.
The 31-year-old and her daughter, three, remain in hospital, along with her older daughter, eight.
The suspect attempted to escape the scene in Clapham in a car but crashed into a stationary vehicle, then ran.
Police believe he is known to the family, but said they were not yet clear on their exact relationship.
Supt Gabriel Cameron told reporters on Thursday he had “no idea” what Ezedi’s motivation may have been, but that he was “wholeheartedly confident” he would be caught.
He said Ezedi is believed to be from the Newcastle area, and the car left at the scene, a Hyundai, belonged to him.
He may have been known to police, Supt Cameron added.
“While this appears to be a targeted attack, he is a dangerous individual, and we urgently need to find him,” the Metropolitan Police said earlier on Thursday.
Supt Cameron said the suspect was last seen in the north London area, in Caledonian Road, and if people see him they should not approach him, but call 999.
There was a heightened police presence in Caledonian Road on Thursday afternoon, including unmarked cars with blue sirens and police vans.
Twelve people in total were hurt in the attack. Out of four members of the public who tried to help, three went to hospital with injuries – two women in their 30s and one in her 50s. Police say they “bravely came to the aid of the family” and have now been discharged from hospital.
The London Ambulance Service said it sent a response team, including three ambulance crews, to the scene after receiving a call about an incident near Clapham Common just before 19:30 on Wednesday.
A man in his 50s declined medical treatment for minor injuries he suffered at the scene.
Five officers who were injured as they responded to the attack have left hospital after receiving treatment.
Some of the burns the mother and her daughters suffered in the attack were “quite substantial”, Met Police chief Sir Mark Rowley told the BBC on Thursday, but added he did not have a full picture of their injuries yet.
They were attacked on Lessar Avenue, near Clapham Common, at 19:25 on Wednesday evening. Police were called following reports of an attack with a suspected “corrosive substance”.
One witness told the BBC that the mother cried “I can’t see, I can’t see” as he tried to help.
Police have urged any members of the public who saw what happened to call 101 quoting reference CAD 7790/31Jan.
Officers have also asked local residents and drivers to check their doorbell and dash cameras for any footage that might have captured a man fleeing the area.
A crime scene is now in place and is likely to remain there for some time, police say.