MINNEAPOLIS (WCCO) — Police say a 23-year-old man is in custody after a 75-year-old man was found with grave injuries Wednesday afternoon in south Minneapolis.

Officers believe there was a verbal exchange on a Metro Transit bus between the victim and a the suspect on the 2900 block of Chicago Avenue at about 2:30 p.m. When the victim got off of the bus, the suspect and three other people followed him.

Police said the victim was attacked, and then fell and struck his head. He is being treated at Hennepin Healthcare.

The Minneapolis Violent Criminal Apprehension team and SWAT personnel located and arrested the suspect Thursday in south Minneapolis. He is expected to be charged with aggravated assault.