Prosecutors said that although it was Salman Abedi who blew himself up amid young Ariana Grande fans flooding out of a concert in May 2017, his brother was just as guilty “as if he had selected the target and detonated the bomb himself”.
Duncan Penny QC told the Old Bailey that the explosion was the “culmination of months of planning, experimentation and preparation by the two of them”.
“This defendant is just as guilty of the murder of the 22 people killed as was his brother,” he said.
“He is equally guilty of the attempted murder of many others and in doing so, he was guilty of agreeing with his brother to cause an explosion or explosions of a nature likely to endanger life.”
The court heard heard that as well as the 22 people killed, including several teenagers, police had identified almost 1,000 other victims.
Of those, 273 people were physically injured and 670 have reported psychological trauma following the explosion.
Mr Penny said the bombing was a “shared goal” of the two brothers, although it would be Salman who detonated the device.
He told the jury that both men had obtained precursor chemicals for the improvised explosive device (IED), then attempted to distance themselves from the purchases by using fake identifies and other people’s bank details.
The prosecutor said that Mr Abedi “obtained and experimented with” metal containers for constructing an IED, fashioned improvised cylinders to be used as detonated and obtained a property in outer Manchester where the bomb could be manufactured and stored.
The 22-year-old was allegedly involved in the purchase of screws and nails to “kill, maim and injured as many people as possible in the detonation”,
Mr Penny said that shortly before the brothers both returned to Libya in April 2017, Mr Abedi purchased a Nissan Micra that was used by the pair as a storage facility for their bomb-making equipment.
“This body of evidence suggests that the defendant in this case, the surviving brother, is just as responsible for the crimes which resulted in so much death, injury and damage following the detonation of the bomb on 22 May 2017,” he added.
“The law is that Hashem Abedi is just as responsible for this atrocity and for the offences identified in the indictment, just as surely as if he had selected the target and detonated the bomb himself.”
Mr Abedi, originally from Manchester, denies 22 counts of murder, attempted murder and conspiring with his brother to cause explosions.
The trial continues.