From the day that 67-year-old Altimese Roberts was murdered in her Darby Township home during a botched robbery, police suspected that her son's girlfriend, Yolanda Certaine, was behind it.

A year later, it's no longer just a suspicion, Sgt. Len McDevitt said yesterday.

Certaine was arrested Thursday - on what would have been Roberts' 69th birthday - and charged with murder, robbery and related counts for allegedly setting up the December 2007 early-morning home invasion in Delaware County.

McDevitt said the 30-year-old "career thug" had been bragging to two cell mates about her role in the robbery while jailed in Philadelphia on unrelated offenses.

Police say Certaine, of 68th Street near Upland in Southwest Philadelphia, lured her then-boyfriend, Gordon Roberts, out of his mother's Clifton Avenue home, where he had been living, so that gunmen could break in and steal his cocaine and drug money.

They bound and gagged Altimese Roberts and her teenaged grandson with duct tape while searching for the loot, the grandson told police.

Roberts, a mother of eight and grandmother of 22 who worked for 35 years at the Franklin Mint, was found later face down on her bed and unresponsive. The county medical examiner ruled her death a homicide and said that it had been caused by asphyxiation complicated by chronic obstructive pulmonary disease.

"It was for greed," said Roberts' daughter Vernite Jones.

"She ate my mother's food; she came over for dinner," Jones said. "Yolanda had her four children around the family. It wasn't like this woman was a stranger.

"This isn't something you do on the spur of the moment," Jones said, as if speaking directly to Certaine. "You thought this out. To know her was to love her. She knew my mother was a genuinely sweet person. It wasn't for revenge, it was all about greed. Whether it was an accident or not, it was evil for her to do that."

Two witnesses told police in recent months that Certaine had admitted to plotting the robbery, according to the criminal complaint filed this week.

One cell mate said that Certaine had claimed "I'm famous" because the case had been reported in the news media. The other told police that Certaine said that Roberts' death had been an accident and that she had hatched the break-in to steal $40,000 and two kilograms of cocaine from her boyfriend.

McDevitt said he didn't believe that anywhere near that amount of cash or drugs had been stolen. He said investigators were searching for the men who robbed the house, which is across the street from two churches and an after-school program.

"She was always a suspect right from the beginning," McDevitt said of the two jailhouse witnesses who are expected to testify at Certaine's trial. "We were getting closer and closer, and this was the nail in the coffin."

Dana, another daughter of Roberts', said Certaine had committed the crime because she was being evicted and was upset that Gordon Roberts was not paying her rent.

"Plus," Dana Roberts said, "he had found a new girlfriend." *