A Queens man is being monitored at Bellevue Hospital after confessing to murdering his 80-year-old mother with a crutch. Police found the crutch along with a bloody knife after receiving a call from Sergeui Mamontov, who uses the crutch because he only has one leg. Mamontov, who has a history of mental illness also tried to castrate himself, telling police he was "trying to remove the evil." Lyudmila Mamontova lived in the same Far Rockaway......