Mesrine was sentenced to 10 years in prison for the bungled kidnapping; he escaped a few weeks later, but was rearrested the next day. Mesrine and Schneider were acquitted of the murder of Le Bouthillier in 1971. With Jean-Paul Mercier, Mesrine cut through the wire to escape again on August 21, 1972, with five others from the Saint-Vincent-de-Paul prison. Mercier, a wanted murderer, and Mesrine then robbed a series of banks in Montreal, sometimes two in the same day. By this time it was apparent that Mesrine did not have a normal criminal attitude towards minimizing the danger of being caught. Deeply resenting the way he had been treated in the prison, Mesrine and Mercier made an extremely risky attempt to precipitate a mass break out from the maximum security block of Saint-Vincent-de-Paul on September 3, 1972. However, their own break-out had caused perimeter security to be greatly increased and they found the area swarming with armed guards. There was a shoot-out in which two guards were seriously injured and Mercier was wounded before they managed to get away. The boldness of escaped convicts returning to attack a prison infuriated Canadian law enforcement; the escapade predictably led to a hugely increased effort to arrest the duo.