Waldo Grant was born on November 3, 1946, in Bulloch County, Georgia. He was one of the fifteen children of Jerome Grant and Mattie Rucker Grant. Waldo grew up in a large family, and they lived in Statesboro, Georgia. Life in such a big family shaped his early years.

When Waldo turned 16, he became a self-ordained minister for a black gospel church. This role was significant for him, as it gave him a sense of purpose. In 1971, after experiencing a failed marriage, Waldo decided to move north to find a fresh start. He eventually settled in an apartment in Manhattan's Upper West Side.

In New York City, Waldo was described by his neighbors as a quiet loner. Despite his reserved nature, he became somewhat known in the gay community of the Upper West Side.

On September 13, 1973, Waldo Grant murdered 20-year-old Phillip Mitchell. Grant hit Mitchell over the head with a lead pipe and then dragged his body to the roof of 203 West 91st Street. To make it look like an accident, Grant threw Mitchell's body off the roof into a yard. Grant claimed Mitchell demanded money after they had sex and started searching through Grant's closet, but this has not been proven.

Almost two years later, on June 1975, the body of 23-year-old George Muniz was found in a metal trash can in front of 210 West 91st Street. He had been stabbed several times in the throat and back.

On October 3, 1976, Grant killed 22-year-old Harold Phillips in his apartment at 27 East 124th Street. Phillips was beaten to death with a hammer.

Later, on December 29, 1976, the dismembered body of 16-year-old Harry Carillo was discovered in Central Park by children. Grant, who had known Carillo for about six months, had cut his body into three pieces and placed them in three green garbage bags. He used a shopping cart to transport the bags to Central Park.

After being the last person seen with Carillo, Grant became a suspect. He was questioned several times by police over two weeks. On January 10, 1977, Grant confessed to killing Carillo after a five-hour interrogation. He later admitted to the three other murders, stating he had an "uncontrollable urge to kill." On June 30, 1978, he was found guilty of all four murders and received four life sentences to be served concurrently.

Waldo Grant died on June 6, 2023, at the Albany Medical Center in Albany, New York. He was 76 years old.