He was 70 and died in Santa Clarita, Calif., his wife, Rita, said.
"He was a real blue-collar detective," Simpson prosecutor Christopher Darden told the Los Angeles Times Sunday. "He did his job the best he could and he was a fine detective, one of the best."
Vannatter was among the first detectives to arrive at Simpson's mansion in June 1994 after the stabbing deaths of Simpson's ex-wife, Nicole, and her friend, Ronald Goldman.
In 1977, Vannatter arrested film director Roman Polanski in a California hotel on charges of having sex with a 13-year-old girl.
Vannatter joined the Robbery-Homicide division of the LAPD early in his 27-year career and earned a reputation for meticulous work, the Times said.
In the Simpson trial, the former football star's attorneys questioned Vannatter's account, attempting to show he illegally entered Simpson's property. But the judge ruled at a preliminary hearing police had acted appropriately.
After Simpson was acquitted of murder, Vannatter retired from the Los Angeles department and moved to a farm in Vevay, Ind., where he served as chief deputy sheriff.