They say the wheels of justice turn slowly.

But when, after nearly 12 years of widowhood, Mary Ann Nelson learned Alabama authorities had finally made an arrest in her husband's mysterious slaying, she thought a full picture of how and why he died would emerge at last.

Now, two years later, the Petaluma woman and her family are learning to accept that it could be several more years before the man suspected in Bob Nelson's killing comes to trial and investigators reveal what they know, thanks to a crushing backlog in the Alabama courts.

"My friend keeps saying, 'You need to call back there and find out what's going on,' " Mary Ann Nelson, 61, said in a recent interview.

But she already knows the answer: "It's that waiting game."

Bob Nelson, 59, a long-haul trucker who was transporting frozen chicken parts to Florida, was found fatally stabbed July 2, 1999 -- his body and the bedding from the sleeper compartment of his rig dumped on the side of Interstate 85 about 20 miles outside Montgomery, Ala.

His blood-spattered cab was later found at a north Georgia truck stop -- the keys in the ignition and Nelson's heart and blood pressure medications inside.

The refrigerator trailer -- its stinking, rotting load of chicken finally arousing attention -- was found at another truck stop 15 miles away.

The mystifying case languished for more than a decade before DNA analysis of some cigarette butts and a semen stain in the cab led investigators to a suspect, an Amarillo, Texas, man and mainstay of the criminal justice system named Gary Lee Poisel Jr.

Poisel, now 41, was arrested in Texas two years ago and indicted by a grand jury in February 2012 for murder in the course of stealing Nelson's Freightliner tractor rig. He is eligible for the death penalty.

But Poisel is among 15 defendants awaiting trial on capital murder charges in rural Macon County, Ala., a region where diminished court funds and system capacity usually allow only one such trial in a given year, Assistant District Attorney Kalia Lane said.

The presiding circuit court judge on Thursday called two cases for trial in September, hoping one of them would settle before going before a jury, she said.

That means the remaining cases will remain on hold for another year, until the next special trial session is set -- barring an unexpected infusion of cash into the state, Lane said.

Poisel remains behind bars on a no-bail hold but has not been to court since April 16 and has no future court appearances scheduled, Circuit Court clerk Veronica Harris said.

When Poisel's case will be called for trial is anyone's guess, said his court-appointed defense attorney, T. Robin McIntyre.

"It could be several more years before it would actually come to trial, but that might be wrong," McIntyre said.

Alabama's judicial system is structured around circuit court judges who generally oversee multiple counties, spending time in each county during the course of the year.

Macon County is one of four counties in the state's fifth circuit. Its three judges run two-week criminal trial periods each spring and fall during which the court can't come close to clearing the regular calendar.

Moreover, capital cases -- those in which prosecutors seek a death penalty -- are typically scheduled outside the regular trial session, at a rate of about one a year per county, owing to the kind of funding crisis that has crippled courts in states around the nation.

"We just don't have the manpower here to try cases like that," Harris said.

Capital trials each involve two parts: a guilt phase and a penalty phase. There are expert and lay witnesses to round up, perhaps 400 jurors to screen, potential security challenges to address.

"Because they require more expenditures of time and also of personnel, they are done basically on a first come, first served basis in the court system," McIntyre said. "They are much more involved and time-consuming procedurally. We also are facing the fact that they have a reasonable number of capital cases that are pending for trial in Macon County."

Mary Ann Nelson, a retired legal assistant for the Sonoma County District Attorney's Office, is familiar with the sometimes creeping pace of criminal prosecutions.

And she reminds herself that, while she's waited nearly 14 years for justice, Poisel's case is just 2 years old.

The elation she experienced when a suspect was finally identified and arrested -- though it cast her adult children back into mourning -- has helped sustain her through her continuing desire to know how and why her safety-conscious husband was targeted in the first place and exactly what occurred before he died.

The lead investigator, with whom she last spoke last fall, hasn't been able to tell her "anything really of any kind of substance," but assures her "this is the right guy," Nelson said.

"The fact that they even caught the guy is amazing to me," she said. ". . . I still don't know exactly what happened, but at least they have somebody."

You can reach Staff Writer Mary Callahan at 521-5249 or mary.callahan@pressdemocrat.com.