Updated

Three of the four prostitutes whose bodies were found behind a string of seedy motels just outside Atlantic City last year were high on drugs when they died, and a fourth had alcohol in her system, authorities said Monday.

Toxicological tests on Barbara V. Breidor, 42, of Ventnor, showed a high level of heroin in her body at the time of her death, Atlantic County Prosecutor Jeffrey Blitz said.

Two other victims, Tracy Ann Roberts, 23, and Kim Raffo, 35, had high levels of cocaine in their bodies at the time of their deaths, Blitz said. Both of those women were staying in Atlantic City before they died.

Click here to visit FOXNews.com's Crime center.

The levels of drugs in the three women's bodies were high enough to be incapacitating, said Blitz, who would not reveal the exact level for each victim.

"Anyone, especially prostitutes, should be exceedingly careful in dealing with people offering them heroin or cocaine for any reason," Blitz said.

The fourth woman, Molly Jean Dilts, 20, did not test positive for any drug, but had alcohol in her system, the prosecutor said.

The bodies were discovered Nov. 20 behind several motels in Egg Harbor Township, several hundred yards west of the Atlantic City line. Roberts was asphyxiated and Raffo was strangled with a rope or cord. The other two women's bodies were too decomposed to determine a cause of death, but all four cases are being investigated as homicides.

Each was shoeless and had her head pointing east toward the Atlantic City casinos.

Blitz has resisted speculating whether the four were slain by a serial killer, but said there are some similarities linking all four victims, including their occupation, the fact that three had blonde or lightened hair, and the positioning of the bodies.

The prosecutor said the bodies could be released to family members on Tuesday now that the required testing has been completed.

Visit FOXNews.com's Crime Center for complete coverage.