Trovinger had no prior criminal record.
Walls, who has been held at the Washington County Detention Center since May 9, is scheduled for trial in April 1998.
Trovinger pleaded guilty in connection with a March 21 incident in which a woman got into a van in the 300 block of North Mulberry Street.
Police allege the van was driven by Walls and Trovinger was in the back. Once in the van, the doors were locked and the woman was fondled by Trovinger, according to court records.
"Should I shoot her?'' was a statement the woman attributed to Trovinger as she struggled to free herself.
No weapon was displayed, court records said.
The woman said she was driven to the Jefferson Boulevard area where she jumped out of the moving van, court records said.
She was injured in the jump, leading to the restitution figure for medical expenses.
Both Walls and Trovinger were charged in connection with an April 5 incident in which a woman got into a passenger car containing two men in the 100 block of North Walnut Street, and was driven to McDade Road west of Hagerstown, where she said she was sodomized and assaulted by the two men.
She was dropped off there and the men drove away, police said.
Sexual assault, false imprisonment and kidnapping charges against Trovinger were dropped in both cases in exchange for his plea Tuesday, court records said.
The alleged incidents involving Walls acting alone include:
Feb. 15 - the abduction of a woman at gunpoint as she walked along U.S. 40 west of Hagerstown and then raping and robbing her.
Feb. 19 - picking up a woman in the first block of West Church Street, driving her against her will to Salem Avenue, where she was raped, police said.