Brother of assault victim voices motive concerns after police arrest suspect

Police have made an arrest in an assault that took place outside Fuego Tipico restaurant in the Bronx. 
The victim was walking out of the restaurant when the suspect, 55-year-old Van Phu Bui, followed the victim out of the restaurant and punched the victim while wearing gloves.  
Bui is now in police custody, and the motive of his assault is unknown. The victim’s brother says he still worries about why the attack happened.  
“I don't understand why that happened to him,” said the victim’s brother. “When I saw the video, my brother was just standing and no doing nothing with nobody, he was getting ready to go home." 
Police say Bui is being charged with attempted murder. The victim is said to have a fractured skull and is in critical but stable condition.