Local police investigator Vinicius Assunção told journalists that a judge will decide whether Ribeiro will remain in custody during the investigation or be released on bail.
"His attack was very strong and violent, kicking the referee in the head and making him pass out," Assunção said. "The referee had no chance of defending himself."
Ribeiro's club said his contract was terminated after the incident.
"On the exact day when all the red-green family gathered to celebrate the 113th anniversary of Sao Paulo RS, our club faced one of the saddest episodes of its history," club president Deivid Goulart Pereira said in a statement.
"A fateful scene that shocked all people who love not only Gaucho football but all those who just love the sport in general. The contract with the aggressor athlete is summarily terminated. Furthermore, all possible and legal measures in relation to the incident will be taken."