In December 1996, Cerpa led an MRTA commando squad in seizing the Japanese ambassador's residence in Lima, which started what is now called the Japanese embassy hostage crisis. The MRTA's main demand was for the exchange of the hostages for 465 members of the MRTA in prison, including Cerpa's wife Nancy Gilvonio, the Chilean members of the organization, and U.S. citizen Lori Berenson. The government rejected the demands, and on April 22, 1997, after 126 days, a 140-man team of commandos of the Peruvian Armed Forces stormed the Japanese ambassador's residence to rescue all the hostages. One hostage and two soldiers died in the assault, as did Cerpa along with the rest of the MRTA squad.