Former Beinecke Rare Book and Manuscript Library employee Benjamin W. Johnson pleaded guilty Monday to stealing first-edition novels and rare historical signatures from Yale last summer and selling them over the Internet from his University of Wisconsin-Madison dormitory room.

Prosecutors struck a deal with Johnson, 22, of Hamden, that required him to admit to three counts each of first-degree larceny and first-degree criminal mischief, out of 23 original charges filed against him. Johnson will face a maximum of two years in prison when he is sentenced June 14.

Johnson worked in the Beinecke Public Services department last summer as a temporary employee.

In October, police recovered about $2 million in artifacts from Johnson’s bedroom in Hamden and his dorm room at the University of Wisconsin, where he was an undergraduate until withdrawing last fall.

The stolen items included a 1780 letter from George Washington to the French Gen. Rochambeau valued at $350,000 and three copies of “Moby-Dick” worth $125,000, as well as a slew of other historical books and documents — some of which Johnson mutilated in order to remove valuable signatures.

The plea bargain will also require him to make restitution for the items he stole by relinquishing all of his $52,000 bank account to authorities and making monthly payments — a probation officer will determine the exact amount — to the University, New Haven State’s Attorney Michael Dearington said.

The agreement prohibits Johnson, whose father is a Yale employee, from setting foot on the Yale campus while he is on probation for five years after his release from prison. It also requires him to undergo psychiatric treatment and substance abuse screening, Dearington said.

Repeated calls to Johnson’s Hamden home were not returned yesterday.

Penn Rhodeen, Johnson’s New Haven-based attorney, said Johnson’s “long-standing mental condition” was largely responsible for his criminal activity. Before the thefts, Rhodeen said, Johnson was on a medication program that allowed him to make sound decisions. He said Johnson ran into trouble when he defaulted on his medical routine.

“When people have poor judgement about their [mental health] regimen, they can get into great difficulty,” Rhodeen said. “It’s a tragic situation.”

But others who knew Johnson said he was responsible for his own actions.

“It seems like he got off extremely easy,” said Aaron Lawrence, a Wisconsin student and former roommate of Johnson’s.

“I think Ben can be very thankful that he’s a white kid from a well-off family — because I would be very surprised if our criminal justice system would show a poor youth of color the same sort of mercy,” Lawrence said. “It seems kind of ridiculous to me that they let him off without much more than a slap on the wrist for such a serious crime.”

In October 2001, detectives from the Capitol Police Department in Madison were investigating the theft of a George Washington signature cut from a document housed in the Wisconsin Historical Society. Police first suspected Johnson of that theft because an autograph dealer who was doing business with him told them that all of the signatures Johnson sent her were in unusually good condition.

Although the Madison detectives later determined that Johnson was not responsible for the historical society theft, the original information from the dealer allowed them to develop sufficient cause to obtain a search warrant for Johnson’s dorm room once they learned of the documents missing from Beinecke Library.

Shortly thereafter, Yale police procured a similar warrant to cover his Hamden home. They searched Johnson’s bedroom and discovered numerous historical artifacts that had been reported missing from Beinecke Library, and then promptly arrested him.

Despite the relatively short potential prison term — Johnson could have faced a maximum of more than 250 years if convicted of all the original charges — Yale spokesman Tom Conroy said the University is “satisfied” with the outcome of the case.

And Ed Bardon, one of the Madison detectives who originally investigated the matter, said he is also pleased.

“It was interesting,” Bardon said. “I got to see some nice original documents.”

–Maya Ziv-el of the Daily Cardinal at the University of Wisconsin-Madison contributed to this story.