It's been more than a month since three homeless people were shot and killed in East Orange County.

The accused killer, 47-year-old Leonard Lewis is behind bars, arrested on three counts of first-degree murder. However, investigators admit they are still missing a key piece of evidence -- the murder weapon.

But how will the lack of physical evidence in the case affect the jury's verdict?

“It’s going to be a circumstantial case but they do have a lot of evidence, which is why they were able to get the probable cause arrest him,” said NeJame Law attorney Jaya Balani, who also serves for as a legal analyst at News 13.

Right now, some of that integral evidence can be heard in a chilling 911 call that investigators have not released yet.

However, that 911 call has been summarized in Lewis’ arrest report.

Investigators said Debbie Watson, Lewis’ ex-girlfriend, made the 911 call for help on St Patrick’s Day night, telling a dispatcher that her friend Richard Button had been shot.  On the 911 call, investigators said another male voice was heard and then the sound of gunshots.  After those deadly shots, Watson can be heard saying, “he just shot another one” (referring to Todd Lemme) and Lewis was heard in the background saying “yep, another one dead.”

“It’s not a slam dunk case for the state, but it’s also going to be a tough case for the defense,” Balani said.

Meanwhile, Balani told News 13 Lewis’ defense attorney will have to go on the offensive during trial and try to claim deputies botched the initial investigation. Balani said that's because none of the three victims’ bodies were found until the next morning on March 18.

The Sheriff's Office is conducting an internal review to figure out why the 911 dispatcher(s) did not pass along key information on the night of March 17 that may have lead deputies to find the victims’ bodies sooner.

Meanwhile in the arrest report, deputies explained how they briefly detained Lewis the night of the shooting at a nearby abandoned home on the property where the bodies were found. They said he was drunk and told them he didn’t hear any gunshots.

Deputies let him go that night because they didn’t have any evidence to tie him to the murders. Once they heard the full 911 call, they pegged Lewis as a person of interest and eventually their prime suspect. 

“We would obviously like to recover the firearm that’s involved," said Detective Mike Ruggiero during a news conference April 3. "Not only to get it off the street but to have it for comparison purposes.”

Lewis has not confessed to any wrongdoing. It will be up to investigators to prove their case without him and the murder weapon.

“But without the gun, they still have the voice from that night with the 911 call because of the amount of words that he said," Balani said. "Someone who does voice analyzing could try to pin it to him, showing that he was there at that time frame.”

Balani said unless more evidence is uncovered, the best case state prosecutors have right now is to use a pending medical examiner’s report to approximate when the victims died, and match that up with the timeline established by Watson’s 911 call.

“It is a circumstantial case. They don’t have any eyewitnesses. They don’t have a gun. They can’t have someone testify that he did it. I saw him do it. All we have is a voice, a time frame and bodies,” Balani said.