The Utah County attorney's office on Thursday charged a 16-year-old Las Vegas youth as an adult in connection with the death of a Fillmore man during a car chase Monday.

Steven Edward Floyd was charged before 4th Circuit Judge Robert J. Sumsion with manslaughter, a second-degree felony, and evading a police officer, a third-degree felony. Sumsion appointed public defender John Musselman to represent Floyd.Police officers were pursuing a vehicle at high speed Monday night when it hit a car driven by Boyd Day, 69, in a south Provo intersection. Day was killed and his wife, Mary Day, 52, seriously injured.

Payson police began chasing the car on U.S. 6 near Benjamin, then north on I-15, where police from several other agencies joined in. Speed of the chase exceeded 90 mph at times.

The car left I-15 at the University Avenue exit and, traveling an estimated 70 mph, hit several cars at the intersection of East Bay Boulevard, where Floyd was arrested. Police say Floyd had run away from a Las Vegas youth detention facility and is suspected of having stolen a car.

Musselman told Sumsion that he intends to file a petition to return jurisdiction of Floyd's case to juvenile court. He asked the preliminary hearing be postponed until a ruling on that petition is made.

Sumsion agreed and also returned Floyd to the Provo Detention Center until juvenile authorities hold a bail hearing on the case next week.

County Attorney Kay Bryson decided to charge Floyd as an adult Wednesday afternoon after meeting with representatives of Provo police and the county's juvenile division.

The criteria used in determining whether to try a minor as an adult are: the seriousness of the offense, past criminal history and whether the juvenile system can provide an adequate rehabilitation program.

If convicted as an adult, Floyd could be sentenced to one to 15 years in prison and fined $10,000 on the manslaughter charge, and less than five years in prison and a $5,000 fine on the evasion charge.