ADRIAN -- With each passing birthday and holiday, Shan Lynch hoped the slaying of her younger sister, Theresa Carey, would be solved some day.

After nearly 32 years, that day came Wednesday when Anthony Guy Walker, 53, pleaded guilty in a Lenawee County courtroom to killing Ms. Carey, her friend, Yolanda Torres Madison, and a Washtenaw County man.

"One of the questions that has always been on my mind and the minds of my family and relatives is why anybody would be so inconsiderate of ... another human being," said Mrs. Lynch, of LaSalle Township in Monroe County.

Walker, who is serving a prison sentence for a 1996 rape conviction in Wayne County, is facing mandatory life sentences on each of the open murder counts. Circuit Judge Timothy Pickard has set sentencing for Jan. 21.

In addition, Walker admitted his role in two other unsolved homicides. He did not enter pleas to the crimes that date to 1975.

Assistant County Prosecutor Doug Hartung said the pleas brought to an end more than three decades of unanswered questions for the victims' families and the guarantee that the killer will never be released from prison.

"I think they were very relieved to know that the person who is responsible was brought to justice on all these crimes," he said. "Walker is going to die in prison, whether he pleads to one murder or a thousand murders. The result will be the same."

Ms. Carey, 19, and Mrs. Madison, 24, were shot and killed inside Mrs. Madison's home on West Maple Avenue, across from the old county jail on Jan. 15, 1979. Investigators said Walker, then 19, set the house afire, causing Mrs. Madison's 11-month-old daughter, Jessica, to die from smoke inhalation.According to the assistant prosecutor, Walker admitted in court he entered the house to commit a robbery and ended up killing the women when he went into the house.

Walker also pleaded guilty to the shooting death of Floyd Beatty, who was found March 2, 1979, near the back door of his home, just across the Lenawee County line in Washtenaw County.

Mr. Hartung said Walker was paid $2,000 to kill the victim in what investigators believe was a drug-related crime.

He said investigators don't know who was responsible for hiring Walker to carry out the murder.

The other crimes confessed to by Walker were the killing of an Adrian woman and the 1986 murder for hire of a prisoner at a now closed Jackson correctional facility, the prosecutor said.

The decomposed body of Arlene Salcedo was found Sept. 22, 1975, in a field two miles south of Blissfield.

Mr. Hartung said Walker admitted that, while he was housed at Riverside Correctional Institution in Ionia, Mich., he enlisted an inmate at the former state Southern Michigan Institution near Jackson to kill Daniel Staggs, 40.

He said the inmate who was responsible for the killing has died in prison.

At the time, Walker was serving a 10-to-15-year sentence on a September, 1979, conviction in Lenawee County for assault with intent to commit criminal sexual conduct.

Prosecutors and police said the use of DNA was instrumental in bringing to light the crimes committed by Walker.

Although not available in 1979, evidence that contained Walker's DNA in the murder of Ms. Carey and Mrs. Madison was obtained early in the investigation.

Adrian Police Chief Terrence Collins, then a young sergeant on the department, was a close friend of Ms. Carey's family and graduated from high school with Mrs. Lynch. He recalled that he identified Ms. Carey after he arrived at the burning house and was assigned to comfort the family.

He was promoted to chief in 1980 and when he left the department in 1987 to pursue a job in private business, he said his one regret was not solving the murders of the two women. He returned to the department in 2004 as deputy chief, only to be appointed police chief again a short time later.

"This case never left me, not for a day. It stuck in my craw because we didn't solve it," he said.

Before the chief returned, detectives had begun working on the analysis of the DNA evidence and formed a small task force with Michigan State Police and prosecutors to concentrate on the case.

"I can't say enough about what my detectives did. They worked their tails off," Chief Collins said. "It is extremely gratifying to solve this case."

Mrs. Lynch said Chief Collins and detectives on the department worked tirelessly on the case and kept her family up to speed on the investigation's progress.

"I can't say enough about what that whole group of individuals did through the years," she said. "If Terry Collins hadn't pursued it and pushed, I don't know where we would be."

Mr. Hartung said his office filed charges against Walker in the deaths of the two women in May, and then entered in plea negotiations that produced confessions to the other crimes.

Ms. Carey graduated from Adrian High School seven months before she was murdered and was working at an Adrian factory and living with her family on Frank Street in Adrian.

"She was a normal 19-year-old," said Mrs. Lynch, the eldest of 12 children.

Robert Carey, now 49, who is a year younger than Ms. Carey, said he and his wife observed his sister's birthday by going to a restaurant for dinner.

"She is still part of our lives. We still think about her a lot," he said.

Contact Mark Reiter at: markreiter@theblade.com, or 419-724-6199.

First Published December 10, 2010, 4:40 a.m.