Updated at 6:01 p.m. April 20, 2011:
Police have arrested Elex Murphy of North St. Louis and are holding him without bond.
A police investigation revealed the attack was part of a game which involves unprovoked attacks on innocent bystanders.
An investigation to identify other suspects is ongoing.
St. Louis police say they have arrested an 18-year-old man in connection with the beating death of a 72-year-old Vietnamese immigrant and the assault of the 59-year-old wife.
St. Louis Public Radio is a service of the University of Missouri-St. Louis.