A 16-year-old Renton boy pleaded guilty as an adult Tuesday in the assault and robbery of a man at the Metro Transit Center in downtown Renton May 5.

Solinuu Leae, 16, was charged with first-degree robbery and second-degree assault.

King County Superior Court Judge Barbara Mack will sentence Leae Sept. 30 at the Norm Maleng Regional Justice Center in Kent. The sentence range is 51 to 68 months in prison.

Until he’s 18 years old, Leae would serve his time at a juvenile facility run by the Juvenile Rehabilitation Administration and not the state Department of Corrections, mostly likely the maximum-security Green Hill facility in Chehalis, said Ian Goodhew, a spokesman for the King County Prosecutor’s Office.

At 18 he would transfer to the state correctional facility in Shelton, where he would be classified and then sent to a state prison, he said.

Leae was initially charged in Juvenile Court, but he stipulated to the state’s request to have him prosecuted in adult court, according to the Prosecutor’s Office.

Leae’s brother Troy Leae and another defendant, Francisco Rondon, both 20, are charged with first-degree robbery for their alleged role in the May 5 attack on the 36-year-old man who suffered a broken arm and broken jaw.