A father and son have been jailed for a bungled revenge plot to kill a Birmingham shop owner, after allegedly recruiting an American woman to carry out the shooting who wore a hijab as a disguise.

Mohammed Nabil Nazir, 30, was sentenced to 32 years in prison, while his father, Mohammed Aslam, 58, was given 10 years after both were convicted of conspiracy to murder Aslat Mahumad, the owner of a boutique clothing shop in Birmingham.

Nazir was also found guilty of possession of a firearm, illegally importing firearms and perverting the course of justice.

The suspected hitwoman was named during the trial as Aimee Betro, a US citizen originally from Wisconsin, who is in prison in Armenia subject to an extradition request after being arrested in July.

She allegedly donned a hijab as a disguise and attempted to shoot Sikander Ali, Mahumad’s son, at a range of six to seven yards in an attack in the South Yardley area of Birmingham on 7 September 2019, but the gun jammed, allowing him to escape.

It is believed Mahumad, who lived nearby, was the intended target of the attack and there was a history of “antagonism and resentment” between the families, the trial at Birmingham crown court heard.

This included a violent confrontation at Mahumad’s clothing boutique in Alum Rock Road in July 2018, which left both Aslam and Nazir, of Derby, with serious injuries. Aslam sustained brain injuries that continued to affect his cognitive function, the court heard, and the windows of their family home were also smashed on the same day.

Judge Drew said the incident in 2018 was the “motive and the motivation” for the “deliberate and planned” revenge attack the following year, which he said would have “amounted to an execution” if the gun had not malfunctioned.

“This was not a spontaneous reaction to events, but a planned revenge attack,” he said. “It would be overstating the case to call what took place as a contract killing, but evidence suggests Betro was rewarded for taking part in this.”

Betro flew to the UK from her home near Chicago in August 2019, the court heard, and came to Birmingham after a brief tour of England that was partly funded by Nazir. “The two of you had done everything you could to encourage and enable Aimee Betro to kill a member of Mr Aslat’s family, whether that was Mr Aslat himself or one of his close relations,” the judge said. “It was only a matter of chance Sikander Ali was not killed. He was shot at close range, almost point blank.”

West Midlands police previously described the investigation as “complex and protracted” and said it took “years of unravelling” to pin the culprits down. “Aslam and Nazir were determined to take revenge following a fallout where they were injured,” said DI Matt Marston. “The lengths they went to in trying to make sure they weren’t implicated in pulling the trigger are immense.”

Hannah Sidaway of the Crown Prosecution Service said it was a “methodical and well-planned attack” in which Nazir and Aslam tried to cover their tracks by using an accomplice. She said: “This was a complex investigation involving collaboration between West Midlands and Derbyshire police, the Crown Prosecution Service and the US authorities. It involved obtaining evidential material from the US including forensic samples to link the offenders with evidence from the crime scenes.”