A family in Philadelphia is desperately seeking answers after their 17-year-old son experienced a severe brain injury during an assault in a Pennsylvania park earlier this month.
Shawn Rinnier, a resident of Bryn Mawr, is currently in a rehabilitation center recovering from an attack that occurred around midnight on May 10 in Wissahickon Park, Chestnut Hill. Instead of celebrating his upcoming graduation, Shawn faces a challenging recovery.
“Witnessing your child in such a condition is heartbreaking,” expressed his mother, Susan Rinnier. “His face was extremely swollen, he had deep cuts, was on a ventilator, and wore a neck brace.”

Shawn, a student at Saint Joseph’s Prep, recounted attending a Tiki-themed party with classmates and peers from other nearby schools when multiple altercations erupted.
“I was trying to avoid getting involved in a fight. My friend was already in one, and as I stood behind him, I ended up being attacked,” Shawn explained.
His parents were alerted by a doctor and some of Shawn’s friends at 2 a.m. on Mother’s Day, notifying them that their son was hospitalized. Shawn was subsequently moved to the intensive care unit for further treatment.
“He was the first team all-Catholic tennis player this year. They were going to state on Tuesday. So Sunday, we were like, ‘Shawn, you gotta wake up, you have states, you have AP tests,” said Shawn Rinnier’s father. “We were trying to motivate him, and we got no response the first few days.”
Shawn Rinnier said his memory of the night remains blurry. His parents said investigators told them a good Samaritan found him alone in the woods and called 911.
“She said there were hundreds of kids in and out of the woods, and she was pretty intimidated, then she saw Shawn on the road and was like, ‘Oh my God, is this kid OK?’” his father said.
Philadelphia police said they are using videos of the incident as part of their investigation.
“People that are being questioned are just not either willing to talk or afraid to talk or not wanting to get their friends in trouble,” Susan Rinnier said.
Rinnier spent nearly a week in the hospital before being transferred to a rehabilitation center, where doctors diagnosed him with a traumatic brain injury. His family said doctors expect his recovery to take more than a year, delaying his plans to attend college.
“He was really looking forward to going to college next year, and that’s just out of the cards, so we’re working on a letter to the University of Florida to get him deferred for a year,” his father said.
The school’s president sent a letter to the school community asking for prayers and sharing that Rinnier is expected to attend graduation on Sunday.
“Luckily, I do get to attend graduation, so I get to be with my friends being here every day. It changes a lot,” Shawn Rinnier said.
Susan Rinnier said the family is still searching for accountability.
“I just really want to know what happened and somebody to take accountability,” she said.
Rinnier said he plans to walk across the stage at graduation Sunday instead of using his wheelchair. Philadelphia police and the family are asking anyone with information or video from that night to come forward to assist investigators.
Copyright © 2026 WPVI-TV. All Rights Reserved.