Bexar County sheriff's Sgt. Kenneth Van was stopped at a red light on May 28, 2011, when Mark Anthony Gonzalez pulled up and fired more than 25 rounds from an assault rifle into the officer's cruiser. At his trial last month, a friend told jurors that Gonzalez chuckled when he let slip that he'd just murdered a cop.

Gonzalez was the third murderer sentenced to death by a Texas jury this year, which means the state with the most active execution chamber in the country will see fewer death sentences in 2015 than in any other year since the U.S. Supreme Court reinstated the death penalty in 1976.

In the 1990s, Texas courts sent as many as 48 inmates to death row every year. But that number has steadily tracked downward over the past decade and a half — primarily, experts say, because Texas lawmakers gave juries the option of a true life-without-parole sentence in 2005.

Still, Texas saw 11 death sentences in 2014. This year, it seems, there will be at most four. Kathryn Kase, executive director of Texas Defender Service, a nonprofit that represents death row convicts, calls that number “exceedingly low” and credits the drop in death sentences in large part to society's shifting attitudes on capital punishment.

U.S. Supreme Court Justice Stephen Breyer covered many of the reasons juries might now be less inclined to sentence a convicted murderer to death in his 40-page dissent this year questioning whether capital punishment, as it is currently practiced, should be considered unconstitutional. Breyer pointed to studies that consistently show whether someone is sentenced to death is more often determined by race, geography or the kind of lawyer you get than the heinousness or brutality of the crime.

“I see discrepancies for which I can find no rational explanations,” Breyer wrote. “Why does one defendant who committed a single-victim murder receive the death penalty (due to aggravators of a prior felony conviction and an after-the-fact robbery), while another defendant does not, despite having kidnapped, raped, and murdered a young mother while leaving her infant baby to die at the scene of the crime…?”

Breyer also pointed to the fact that capital cases are riddled with errors (state and federal courts have identified prejudicial errors in 68 percent of capital cases that come before them) and fundamental shifts in forensic evidence (DNA testing, among them) to say “there is significantly more research-based evidence today indicating that the courts sentence to death individuals who may well be actually innocent.” He even specifically referenced the cases of two Texas men who were executed for crimes they almost certainly did not commit.

All of that trickles down to juries empaneled for capital murder cases and the voting public that elects district attorneys. “What you're seeing is society backing away, even in Texas, from death sentences,” Kase said. Indeed, polls now indicate that the majority of Americans favor life in prison over a death sentence.

Meanwhile, Texas appears to be doing everything in its power to ensure the state can execute those who remain on death row. In 1994, Texas executed 14 inmates. Last year, prison officials executed ten death row prisoners. Texas is slated to execute its 13th and final prisoner of 2015 next month.

“Even with the drop in sentences, what you see is executions at the level they were 20 years ago,” Kase said.

Defense attorneys have claimed that, amid problems finding a supplier for lethal injection drugs, Texas prison officials started manufacturing them on their own. Last week Buzzfeed News discovered that prison officials in Texas, along with those in Arizona, tried to illegally import lethal injection drugs from India this summer (Food and Drug Administration officials ultimately blocked the shipments). And according to court records, Texas has even provided execution drugs to at least one other death-penalty state, making sure prison officials there can also continue to carry out lethal injections. Executions have become a state export.

In recent years, lawyers for death row inmates have pointed to the drugs used to execute inmates, arguing states are effectively experimenting on prisoners and performing executions that might violate the Eight Amendment's ban on cruel and unusual punishment. Texas, like other death penalty states, has had to turn to unregulated compounding pharmacies for lethal injection drugs once drug manufacturers, largely because of mounting pressure from anti-death penalty activists, started refusing to sell states drugs for use in executions.

So the sedative that Texas now uses to execute inmates, pentobarbital, has become increasingly difficult to get. The drug, which is preferred by prison officials because of the deep, coma-like sleep it produces, is apparently so hard to get that before Clayton Lockett's botched execution in Oklahoma last year, prison workers there literally drove around the state, walking into pharmacies to ask for some pentobarbital. With no luck, Oklahoma officials used another drug; Lockett regained consciousness during his execution and writhed, moaned and groaned while he took 43 minutes to die.

Last month, Oklahoma's governor stopped the execution of another man, saying the state prison officials discovered they actually had the wrong drug. Meanwhile, an autopsy revealed an Oklahoma inmate in January was actually executed with the wrong drug, potassium acetate, instead of potassium chloride (among the man's last words: “My body is on fire”).

The execution drug crunch has led some states, like Ohio, to temporarily halt executions altogether. Yet Texas has somehow continued to keep a steady supply of pentobarbital on hand to kill inmates, despite the periodic warnings the state is running out of death drugs. How Texas is getting its lethal injection drugs, however, has been a mystery since 2013, when the Woodlands Compounding Pharmacy backed out of its deal to sell them to prison officials once the arrangement was made public.

Perhaps Texas is making the drug on its own, as lawyers for one Oklahoma death row inmate alleged in an appeal filed last month. The lawyers wanted Oklahoma officials to consider other options besides midazolam, like buying pentobarbital from Texas. They even pointed to purchase orders that show Texas prison officials this summer sent the Virginia Department of Corrections three 50-milimeter packages of the drug.

State prison officials have flatly denied that they're making execution drugs themselves, which would mean Texas has to be getting them from somewhere — maybe in secret from some undisclosed compounding pharmacy.

But clearly the state wants a Plan B. The FDA confirmed last week that it had seized a shipment of sodium thiopental, another execution drug, Texas had tried to import — reportedly from India. TDCJ spokesman Jason Clark told the AP the drugs were legally purchased, and that the state got an import license from the U.S. Drug Enforcement Agency before the sodium thiopental was shipped.

While Texas hasn't used that drug in executions for some three years, Clark told the wire service prison officials want to “explore all options.”

