Debra Renfors, 46, was found beaten to death and sexually assaulted in her apartment in the 1000 block of North Washington Street in Lansing, Michigan, on August 9, 2007. Her murder was the third in a two-week span that summer, a cluster investigators linked to a pattern of brutal attacks on women that suggested a serial offender.

Renfors had moved to Lansing from Mt. Clemens about seven years earlier and was reportedly trying to leave prostitution, working instead cleaning homes. Her apartment building had been the scene of another homicide in 2004, when Barbara Jean Tuttle was killed, a coincidence that investigators noted while examining the string of slayings.

Police later arrested 27-year-old parolee Matthew Emmanuel Macon, who confessed to seven killings and to the five homicides from summer 2007. Macon was tried and convicted for two murders and an assault and received life without parole. Although he was the prime suspect in Renfors’s death and authorities expressed confidence in his responsibility, prosecutors did not pursue formal charges in her case.

Did anyone who knew Debra Renfors or lived near North Washington Street in 2007 see or hear anything that might help explain what happened that August?