Surveillance video shows the suspect throwing the man to the ground and punching him repeatedly.
PHILADELPHIA (WPVI) -- The suspect accused of brutally attacking a man with special needs on the Broad Street Line back in March has been arrested, authorities announced.
SEPTA police say 31-year-old Sieed Thomas has been charged with aggravated assault, simple assault, harassment, and related offenses.
Police say the assault happened on March 14 around 8:30 p.m. as the northbound line train approached the Cecil B. Moore Station in Philadelphia.
Thomas allegedly assaulted a 25-year-old man with autism before fleeing the scene, investigators said.
Surveillance video shows the suspect throwing the man to the ground and punching him repeatedly. Witnesses said the assault was unprovoked.
The victim, who attended Temple University, suffered injuries to his face. His family identified him as Isaiah Miller.
Isaiah's mother spoke with Action News on Sunday about the relief of knowing his alleged attacker is behind bars.
"He gave a thumbs up, now that the person is behind bars he feels really good about it," said Beth Miller, Isaiah's mom.
Miller says she never gave up hope and kept sharing Isaiah's story until the suspect was caught.
"It's been two days shy of the eighth week since the incident happened, and eight weeks feels like eight months that that person has been walking around, so this is just the beginning of some sense of healing," she said.
SEPTA authorities say video from the incident helped investigators identify Thomas.
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Miller told Action News she would not stop raising awareness until the suspect was caught. Now, she's encouraging others in similar cases to do the same.
"If you give up, nothing is going to happen. But if you continue to plug away at it and keep yourself out there, keep the story out there, it's only going to eventually bring that person in and start that process for justice," she said.
Knowing Thomas is behind bars also gives Miller a greater sense of safety, not just for herself but for Isaiah.
"He continues to take SEPTA so I at least know he will not run into that attacker as he comes and goes on a day-to-day basis," she said.
It's been a major week of achievements for Isaiah and his mother. Firstly, Isaiah graduated from Temple University on Thursday as he overcame this traumatic experience.
"He's not a victim. He's a survivor of the brutal attack," said Miller.
Secondly, Sunday is Mother's Day, and Miller says it may be the most memorable one yet.
"It's the best gift I never knew I wanted or needed," she said. "It feels like the very beginning of the healing journey for me."