Eric Lange was an assassin for hire.
Carlo Casagrande hired Lange to kill Peter Malone, an English investigative reporter. Lange completed this task, but not before Malone talked to Gabriel Allon. Lange also took Malone's computer. As he left Malone's residence, Mordecai photographed him. Lange later read about Gabriel's background in a file on the computer. Lange used his contacts within the Palestine Liberation Organization to track Gabriel to Rome but his attempt to kill Gabriel was unsuccessful.
Lange met with Casagrande in Zurich and accepted the contract to kill Marco Brindisi.
On the day of the pope's speech at the synagogue, Lange went to the Vatican. He first went to the Pope's study where he left an envelope on the pope's desk. Leaving the papal study he went to Marco Brindisi's office and killed him.
He escaped on a motorcycle.