The details unveiled by police Monday offered the most thorough accounting yet of the crime that spooked one of Philadelphia's toniest neighborhoods.
Still, they offered little solace to McGovern's friends, who in interviews Monday described him as an adventurous, fun-loving guy who was always the life of the party.
"Anyone who's ever had contact with him, I guarantee, had a smile on their face within 30 seconds of talking to him," said Patrick Lavelle, a lifelong friend from Churchville.
Alex Iuliano, who met McGovern about 10 years ago, said: "He lit up the room and made you feel comfortable or close, like you've been a friend for a while."
Neither viewed McGovern as the kind of person who would instigate a fight with a stranger. Lavelle said he could not picture McGovern's arguing over a hockey hat - McGovern didn't even like the sport, he said.
Attempts to reach relatives of McGovern and Simminger were unsuccessful Monday.
At a news conference, Clark described the altercation he said led to McGovern's death.
Clark said video surveillance showed McGovern and his group passing Simminger on the southern outer sidewalk of Rittenhouse Square early Sunday.
McGovern appeared to say something to Simminger, Clark said, and witnesses said it was about the hat. Simminger, who has a prosthetic leg, then turned and walked up to McGovern.
After a brief exchange of unpleasantries, Clark said, "fists start swinging, they [went] to the ground," and McGovern ended up on top of the pile.
That's when Simminger pulled a knife, Clark said, and plunged it into McGovern's chest several times.
McGovern was taken to Hahnemann University Hospital, where he was pronounced dead at 3:36 a.m. police said.
Simminger, who Clark said lived either in Blackwood or with his sister in Media, was found by police after making his way to the Philadelphia VA Medical Center, 3900 Woodland Ave. He did not appear to be intoxicated, Clark said.
A preliminary hearing is scheduled for March 30. Simminger was charged with murder and possession of an instrument of crime.
Clark said Simminger was a military veteran, but did not specify of which branch. In the last two decades, records show, he has pleaded guilty to crimes including terroristic threats, corruption of minors, driving under the influence, and simple assault.
On Facebook, his profile shows him wearing a blue Devils hat, a cigarette dangling from his mouth. Other photos he posted to Facebook show the Devils logo, as well as logos for New York and Minnesota teams.
McGovern grew up in Churchville as the middle of three brothers, Lavelle said.
A 2009 graduate of Council Rock High School South, he recently had become a sprinkler fitter like his father, and was completing an apprenticeship in the trade, said Lavelle, who met McGovern at Churchville Elementary School.
Lavelle said his friend grew up to be especially passionate about music.
Iuliano said McGovern posted YouTube videos of rap songs under the name "The Professor." But he loved to play guitar, too, writing songs or playing acoustic covers of songs by artists including Jack Johnson and Dispatch, Iuliano said.
Social media overflowed with remembrances of McGovern.
"It would've been twenty years that we have known each other and twenty years of seeing you constantly making everyone around feel happy and making everyone laugh," one friend posted. "I can't believe you were taken from the world so soon and words can not describe how much you will be missed."
Another friend wrote on Twitter on Monday morning: "heaven gained another good one yesterday."
Lavelle recalled a summer night at the Shore that encapsulated McGovern's bold spirit.
After the Wildwood lifeguards had left at 5 o'clock, McGovern and Lavelle swam to a buoy maybe 300 yards off shore.
Exhilarated at first, they soon realized they had to swim back against the current.
When they returned to shore, they collapsed on the sand from exhaustion.
Onlookers told them they were crazy, but Lavelle knew that McGovern simply loved living his life with spirit.
"He had so much heart," Lavelle said, "in everything he did."
Staff writer Emily Babay contributed to this article.