New federal charges are pointing to a connection between two recent shootings at Twin Cities high school graduations.

The disclosure came in charges filed Tuesday in U.S. District Court in St. Paul against Hamza A. Said, 20, of Coon Rapids, and Amiir M. Ali, 18, of Circle Pines, in relation to the shooting outside Mariucci Arena that left two attendees wounded on May 30, soon after the Wayzata High School graduation gathering ended.

Said and Ali are charged with unlawful possession of machine guns. They appeared in court Tuesday and remain jailed without bail ahead of court appearances on Friday. A message was left with legal counsel for both defendants seeking a response to the allegations.

On June 2, Said was charged in Hennepin County District Court with first- and second-degree assault and illegal gun possession in connection with the shooting. The state charges said a man, described by police as 49 years old, was shot in the head while outside the arena with family members. The second victim, 19, was shot in the leg. Officials said both victims were expected to survive.

"High school graduation ceremonies are a rite of passage; a time for friends and family to come together to celebrate one of life's major milestones," Acting U.S. Attorney Joseph Thompson said in a statement Wednesday. "To bring machineguns and violence to such a ceremony is immoral and shameful.

"On behalf of all Minnesotans, I want to express a sense of moral outrage at these crimes and assure the public that the perpetrators will be prosecuted to the fullest extent of the law."

According to the federal charges:

Officers raced to the arena on the University of Minnesota campus and saw a chaotic scene with two ceremony attendees shot. Law enforcement soon found and arrested Said, and recovered a Glock 9 mm semiautomatic pistol equipped with a high-capacity extended magazine and a machine gun conversion device known as a "switch."

On June 3, Minneapolis police officers saw a driver fail to obey a stop sign and speed through the intersection of E. 27th Street and 18th Avenue S. The officers stopped the car and identified its three occupants.

One officer recognized passenger Ali as associated with recent gang-related shootings and known to carry guns.

'Heading to the Edina High School graduation'

"The occupants stated they were heading to the Edina High School graduation ceremony at the University of Minnesota [in Mariucci Arena]," the charges read.

Officers found a Glock 10 mm semiautomatic gun under Ali's front passenger seat. It was equipped with a loaded 33-round extended magazine and a switch. Minneapolis police arrested him, but he was released on June 5 without being charged by the Hennepin County Attorney's Office, according to jail and court records.

"Our office deferred the case against Mr. Ali for additional investigation because the evidence, as submitted, didn't include necessary forensic testing results to overcome likely defenses," said Dan Borgertpoepping, spokesman for the County Attorney's Office. "We requested it be resubmitted for charging consideration when the testing was complete."

On June 6, Ali was arrested by police responding to a shooting at the graduation ceremony at Burnsville High School, and cited for trespassing, according to Dakota County court records.

Ali said in recorded jail calls that, upon his release, he would need a "button," a slang term for a switch or machine gun conversion device, the federal charge noted.

Two 18-year-olds, Abdikani Mukhtar Abdiwahab, of Bloomington, and Abdulahi Jama Ali, of Shakopee, have been charged on suspicion of driving by the high school and opening fire at suspected gang rivals while ceremony attendees were leaving.