Michigan State Police have received DNA results from several suspects in the 1970s "Oakland County child killer" investigation, Local 4 reported.

All four samples sent to the FBI laboratory in Quantico, Va., were a negative match from samples collected in the investigation, according to police.

One of the DNA samples were from Todd Warzecha, a 54-year-old deceased man, who was the primary suspect in two homicides in the Bay County area in the early 1970s, police said.

Another sample was from John McRae, 71, who recently died in Jackson Prison, according to police. McRae was sentenced to life in prison involving a 15-year-old victim from Harrison, Mich., police said.

The other two suspects whose DNA samples were tested in connection with the slayings were not identified.

The slayings of four children, whose bodies were also left along a roadside, have remained a mystery for 30 years, Local 4 reported. The victims include Timothy King, 11, who was kidnapped on March 16, 1977, outside a Birmingham pharmacy; Mark Stebbins, 12, who was abducted while walking to his Ferndale home in February 1976; Jill Robinson, 12, of Royal Oak, who disappeared on Dec. 22, 1976; and Kristin Mihelich, 10, who was abducted 11 days later from a convenience store in Berkley, according to Local 4 reports.

Police said several tips in the case will continue to be investigated and the negative results will not deter investigators.