According to the probable-cause affidavit, Keefe gave a statement to police late Thursday night - 15 years to the day that Brooks was killed.
Rubenstein declined to discuss a motive but pointed to statements by Brooks' friends in the days after the killing in which they told police that the couple's relationship was strained and that Brooks was second-guessing her decision to marry.
The district attorney noted that $2,579 was stolen from the restaurant. He said Keefe also has been charged with the robbery.
Falls Township Police Chief Arnie Conoline said the big break in the case, which sat dormant for more than a decade before being reopened last summer, came Tuesday, when DNA tests conducted on hair and other forensic evidence found at the scene linked Keefe to the killing. Police said they obtained Keefe's DNA surreptitiously, taking the butts of spent cigarettes from his curbside trash and having the saliva tested at a private laboratory.
Rubenstein said Keefe had always been ``in the universe of suspects - not excludable, but nothing to pinpoint him.''
Brooks' stepmother, Betty Brooks, said during an interview in her Warminster home yesterday that she always ``had a gut feeling that he did it'' and that she had shared that feeling with authorities.
On the other hand, George Brooks, the victim's father, said he had long felt assured that Keefe was not involved.
``They were engaged,'' he said. Keefe even came looking for Brooks, 25, on the morning her body was found. The couple said Keefe was sitting in the kitchen with them when police came by and told them their daughter had been murdered.
Both the father and stepmother said they were grateful to police.
``I was shocked, and then I was relieved,'' Betty Brooks said as she sat in her living room, where her stepdaughter's picture sat atop a nearby table. ``. . . Now we can go on with some closure.''
Terri Lynn Brooks planned to work in human resources when she graduated cum laude with a degree in behavioral science from the University of Maryland in 1980, her parents said. But she enjoyed her stints as a waitress during college and decided on a career in restaurant management.
She went to work at Roy Rogers in June 1983. During the first week of February 1984, she became an assistant manager at the Falls restaurant.
It was a busy week. Two days before her death, she and Keefe had put down a deposit on a honeymoon trip to Hawaii. The wedding was set for that summer. Later in the week, Brooks was to pick out a wedding dress.
On Feb. 3, 1984, Brooks was working the night shift. About 10 p.m., she called Keefe to tell him she would be working late. She told him not to worry, that she would have two ``closers'' with her - teenagers who cleaned up after the restaurant closed.
The teenagers left about 1:30 a.m., and Brooks stayed behind, saying she needed to do some paperwork. The following morning, Brooks' body was found by the restaurant's general manager. All of the exterior doors were locked. The safe was open and empty.
According to the arrest affidavit, Keefe told police he went to the restaurant that night and Brooks let him in. He said that he and Brooks fought, and that he struck her, pushed her to the floor, banged her head on the floor, and stabbed her.
The affidavit said Keefe told police he placed a plastic bag over Brooks' head, then grabbed the money, and climbed out through the drive-through window.
A friend also told police that ``Keefe frequently voiced concerns about money and complained about Brooks' decision to take the job with Roy Rogers, because it was a pay cut from her previous job,'' the affidavit said.
Scrapings taken from under Brooks' fingernails, a single hair, and ``human genetic material'' from the kitchen knife had been stored, along with 90 other pieces of evidence and more than 200 witness statements, in a police evidence locker over the years.
According to the affidavit, tests conducted recently at a private lab, DrugScan Inc. in Warminster, matched the hair, the scrapings, and the DNA material on the knife to Keefe.
Police said they obtained a sample of Keefe's DNA by confiscating trash bags from outside his home on Horseshoe Lane. Inside were Newport cigarette butts, with saliva still present. The saliva was tested and confirmed to be Keefe's.
Over the years, Betty Brooks said she had stopped believing the killer would ever be brought to justice. ``I had just hoped that some day, someone would come forward,'' she said. When police reopened the case, she said, she was encouraged: ``They went at it like a dog with a bone.''
Rubenstein yesterday credited Keefe's arrest to Conoline, who took over as Falls Township police chief three years ago. Conoline personally reopened investigations into the township's two unsolved murders. The other remains under investigation.
``Were it not for Conoline, none of us would be here today and Keefe would not be in custody,'' Rubenstein said. ``These things don't happen by accident. It takes good police work. You can't imagine the man- and woman-hours put into this.''
Keefe is being held without bail in Bucks County Prison. A preliminary hearing before District Justice Jan Vislosky is scheduled for 10 a.m. Friday.
* Inquirer suburban staff writers Lisa Shafer and Jack Brown contributed to this article.