LaDondrell Montgomery had his conviction for armed robbery  and a life sentence overturned thanks to his attorney discovering he was in jail at the time of the crime.

But he's still not a free man. The Houston, Texas, felon remains in jail faced with five more robbery charges.

"He learned from his trouble. But he did have a record and I believe that is what kind of got him into trouble now, "  his father Larry Montgomery, 58, told ABCNews.com. "Some of the people involved [in the cases] knew him from the past, from the neighborhood, and I believe had personal vendettas against him."

LaDondrell Montgomery, 36, has had several stints behind bars, starting in his twenties, which made it difficult for him to remember whether he was in jail or out on a particular date.

His life sentence for armed robbery, which he received in November, was overturned last Thursday after his attorney realized he had an air tight alibi. He was in jail at the time of the crime.

"My son had previously been in and out of incarceration before  and had trouble remembering the dates," the elder Montgomery said.

LaDondrell Montgomery might not have known where he was on Dec. 13, 2009, but he knew one place where he was not- the check cashing store that was held up by an armed robber.

He insisted throughout the trial that he was not the man in the surveillance footage that was used to convict him and sentence him to life in prison.

Montgomery's life sentence was thrown out after his attorney, Ronald Ray, scoured his rap sheet and realized he had been in jail at the time on a misdemeanor domestic violence charge and hadn't been released until nine hours after the crime.

State District Judge Mark Kent Ellis chided Ray and Assistant Harris County District Attorney Alison Baimbridge for being "spectacularly incompetent," according to the Houston Chronicle.

Baimbridge told ABCNews.com prosecutors are typically barred from speaking with suspects.

"That would be considered alibi information. That's information you'd assume you'd get from the suspect or his lawyer," she said.

Ray told the newspaper the barb didn't bother him.

"I have freed a man from a life sentence, so if you want to say I'm incompetent for doing that, I'll accept that with a smile," he said.

For now, Larry Montgomery, who is a bishop with the Nation of God Ministries, said he hopes his son will be exonerated of the other counts and will return to being a productive member of society, something his father said he trying to do.

"He got married and he had a child," Montgomery said. "He went to work for the Harris County Flood Control. Every day, all the time. He was trying to turn his life around as a family man."

It's unclear whether Montgomery has discovered five more iron-clad alibis to get him out of trouble this time.