Toronto police have laid new murder charges in a mass shooting that killed two people and injured almost two dozen last summer.

Nahom Tsegazab has been charged with two counts of second-degree murder, police said at a news conference Thursday afternoon.

He was also charged with attempted murder and 22 counts of aggravated assault.

He made his first court appearance this morning.

Tsegazab, who police say is a member of the Galloway Boys street gang, was previously charged with recklessly discharging a firearm.

The mid-July shooting, which occurred at a community barbecue on Danzig Street in Scarborough, killed 14-year-old Shyanne Charles and 23-year-old Joshua Yasay.

Earlier this month, police charged 18-year-old Malvern resident Shaquan Mesquito with two counts of first-degree murder and several other offences.

Police say Mesquito is a member of the rival Malvern Crew street gang.

The block party shooting was the result of a confrontation between members of the rival gangs, investigators have said.

When detectives announced the charges against Mesquito, they also released composite sketches of two men wanted for questioning.

On Thursday, Staff Supt. Greg McLane told reporters that one of those men had been identified and questioned. Police have not laid any charges against this man.

The second man has been identified by his street name "Juvi" but police say they are still trying to figure out his real name so that he too could be questioned.

Police have always said that there were multiple shooters involved that night and on Thursday, McLane reiterated that theory.

"We have reason to believe that there are at minimum one or two more shooters involved in this investigation," he said.

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