Still no charges filed nearly four months after the murder of an elderly couple in Brentwood

Shawn Gant-Benalcazar and Timothy Parlin remain in custody in connection with Billie and Sidney Shelton's murders.

The two men were already jailed in connection with another Austin murder.

Both men are scheduled to appear in court this week for that case so the real question on the Shelton's neighbors minds is: if police know who did it, why not charge them?

The manicured lawn of the Brentwood home where Billie and Sideny Shelton lived masks the harrowing tragedy that happened inside.

"You think you have your life planned out and then all of a sudden - boom it's all different," says longtime neighbor Marie Taylor.

The Shelton's were found dead In late December. Taylor lives with the chilling reminder everyday.

"I thought I'd be living next door to their daughter until the end of my days, now she doesn't want to live there so who could blame her?," she said.

The suspects? Gant-Benalcazar and Parlin.

"It's a big relief for the whole neighborhood," said Taylor.

When it happened, Austin Police declared a "public safety alert". Many in the community, at the time, said they felt like their neighborhood was under siege.

Gant-Benalzacar and Parlin were already jailed in connection with the December murder of Choir Director Kathy Blair.

Gant-Benalzacar is being charged with Capital Murder. Parlin faces burglary charges, and Austin Police say he drove the getaway car.

The news that the suspects were in custody came in a press conference in late January. Austin police say during an interview Timothy Parlin admitted to dropping Gant-Benalcazar off at the Shelton's home. When he returned to pick him up, Police say, Gant-Benalcazar had property that belonged to the Shelton's.

But charges in the case have yet to be filed.

"For them to come out and actually make a statement or have reason to believe that these individuals might be linked to this other murder then that tells me they've got something more than just an assumption," says Former Travis County Prosecutor Mindy Montford.

Montford isn't surprised that it hasn't happened yet.

"They aren't just going to bring charges just on a co-defendants statement alone. They need to corroborate that with more evidence," she explained.

More evidence she says, that could take some time to wade through.

"My guess right now is that's what they're trying to do. Interview witnesses, review cell phone records, review signals to see where they were and if they can pin point them at different they knew these people, and how they are related or might be related."

She says the fact that the two suspects are in jail is buying police and prosecutors additional time to lay out an air-tight case. She does believe there will be justice for the Shelton's.

For Marie Taylor though, no amount of time that either suspect serves will ever be enough to soothe anyone's pain.

"It's just one of those things that you never get over."

The Brentwood neighborhood is installing a bench in the Shelton's honor, a dedication is expected in the coming weeks.