POOR UNCLE ASSAULTED BY E-SCOOTER RIDER! HELP CATCH THAT IDIOT!

"my dad was assaulted by a rider on an electronic scooter at hougang avenue 7 while crossing the road last night at about 9:30pm. rider is likely staying at paya lebar, chinese man, big size, looks rather muscular. Assaulter claimed to b 60 years old but my dad think he looks 40+. After being attacked, my dad suffered a heart attack
add on: my dad did not provoke the rider. the rider was speeding towards my parent while they were crossing the road, n my dad was avoiding him n the plastic bag he was carrying that contained my dad's raincoat accidentally brushed the man on his helmet. that guy then stopped n assaulted my dad straight away. 2 passerbys rushed to my dad's aid n helped. when my dad said he was gonna call the police, the rider made a run for it. 1 of the passerby tried to chase after the rider but lost him somewhere near paya lebar.
police report has already been made.
please help me to share, we want this guy to be caught!
[update]
thank you everyone for your concerns, i cant reply each n every of u but i really appreciate it. my dad has to stay in the hospital still becuz of his heart attack n injuries. he was punched in his chest n face. cut to his left eye n lips, abrasion to his arms, bruises on his face n forehead, bruises to the back of his head. most of the blows were apparently aim at his face n head. luckily there is no fracture or broken bones but my Dad is a 69 years old man n to b subjected to such brutality is really inhuman."