American police inspector (1875-1946). He was born outside of New Orleans, Louisiana into a poor farming family. The youngest of four brothers, he saw little future for himself as a farmer, especially after his father died when he was 14 and the family's land was divided between his older brothers, leaving him with nothing. Taking a small inheritance with him, he traveled into New Orleans and applied for work as a policeman. The police weren't interested in taking on a 14-year-old cop, but they let him stay in the station's basement and work odd-jobs. When he was 16, some of the police officers started training him in various police duties, and the day he turned 18, he was hired as a police officer.
After spending several years walking a beat, Legrasse received promotions that allowed him to take a more active role in crime-solving, and to his own surprise, he actually turned out to have a talent for solving the big crimes. In 1899, he was instrumental in solving the double murder of an elderly society couple (he trailed the couple's son through a saloon crawl on the night following the murder and found him paying off a group of street toughs -- turned out the son needed to pay off gambling debts and hired some thugs to off his folks). The next year, he helped track down two men who had tortured and killed three prostitutes. In 1902, he was promoted to inspector after he almost single-handedly captured a ring of criminals who had robbed a bank and four saloons.
Legrasse turned down several promotions in the next few years because he was enjoying solving crimes too much. He also courted and married Therese Dumelle, the daughter of a prominent New Orleans businessman, and they had their first children -- twin boys -- in 1904. One of the boys died of scarlet fever in 1906 -- his son's death affected Legrasse profoundly, and he stopped attending mass for several years, telling friends that he refused to sing hymns of praise to a child killer.
The biggest case of Legrasse's career came on November 1, 1907. When the police received word that a fringe voodoo cult was kidnapping and killing residents of a squatters camp in a swamp outside the city, Legrasse was chosen to lead a group of 20 officers to investigate. What Legrasse and his men discovered was a band of 100 people dancing naked around an elevated idol in a remote part of southern rural Louisiana. The mutilated bodies of ten victims were found strung up around the cult's compound. Though his men were horrified almost to the point of hysteria, Legrasse was able to rally them to action. Despite the fact that they were vastly outnumbered, the police used superior firepower and the element of surprise to rout the cultists. Many scattered into the swamp, but the police were able to capture 47 of them.
Most of the captured cult members were either insane or mentally deficient, either through injury or retardation. Most of them appeared to be products of several generations of inbreeding, though some of them were foreign sailors who'd been put off their ships for one reason or another. One of the few coherent prisoners was a 95-year-old Mexican man named Castro, who claimed that the cultists worshipped ancient gods that spoke to them in dreams. Castro believed that the Earth was in the End Times when the gods would return and wipe the planet free of life. He also claimed that none of the cult members had been responsible for killing the ten people found at the compound -- he said that the gods did that themselves. Legrasse suspected there could be other cult members besides the 50-60 who escaped from the camp. However, aside from Castro's testimony and the idol recovered from the cultists' camp, there was very little evidence, which left the case at a near-standstill.
The next year, Legrasse took the idol to a convention of archaeologists, hoping to learn some insight about where the cult came from and whether its members could be traced to a specific area. As it turned out, the scientists were fascinated by the idol, which was made of a greenish stone they couldn't identify. Most didn't recognize the idol, which resembled some sort of octopoid monster with bat wings, but it reminded some of a similar case a few years before involving blood sacrifice among a tribe of Eskimos in western Greenland. The Eskimos had called their idol "Ktulu"; the cult in Louisiana had called theirs "Katloo". That seemed to open the floodgates, because soon afterwards, archaeologists, anthropologists, and police forces worldwide began discovering or recognizing cults worshiping octopoid gods called "Caethaelo", "Khat-Lu", "Thulu", "Lilithu", "Ch'th-lu", and a number of variations. Largely through Legrasse's investigations and intuition, scientists had discovered a previously unknown cult which, though disorganized, spanned the entire world.
Legrasse was as surprised as anyone by this discovery. He received credit in a number of scientific papers and received small awards of recognition from the Archaeological Societies of America, Britain, and France, as well as special awards from the city of New Orleans and the state of Louisiana. Only a few years later, however, he received a minor gunshot wound from a suspect in a robbery case--he made a full recovery, but seemed shaken by the glimpse of his own mortality. That, coupled with the birth of twin girls into the family, is probably why he finally accepted an administrative promotion in 1915. He no longer took an active role in investigations, though he still consulted with other officers on important cases.
Legrasse retired from the police force in 1930, but didn't end up leaving all of his past behind him. In 1939, he recognized elements of the old swamp cult's methods in an article in the newspaper about a seemingly accidental death -- he notified police of his suspicions, and, though skeptical, they investigated and ended up arresting 30 members of a revival of the cult. One of them was an elderly Mexican man named Castro.
Legrasse died peacefully in his sleep in 1945.
"The Call of Cthulhu" by H.P. Lovecraft
Encyclopedia Cthulhiana by Daniel Harms, p. 123