(CNN) - Arkansas' efforts to execute eight Death Row inmates in 11 days this month has refocused attention on the death penalty.
Since peaking in 1999, executions in the US have been gradually declining amid controversy over whether lethal-injection methods are humane.
Capital punishment is still legal in 31 US states. But as the drugs needed for execution get harder to come by, states are getting creative.
Here's how we got to this point:
Opposition to the death penalty is rising ...
In 1994, Gallup found that 80% of Americans supported the death penalty. Fast-forward to today: A poll last October showed the support had fallen to 60%.
... and more states are putting executions on hold
Those are in addition to the 19 states and the District of Columbia, which have outlawed capital punishment. Since 2009 alone, Connecticut, Delaware Illinois, Maryland and New Mexico have abolished the death penalty. Nebraska repealed in in 2015 but reinstated it last year.
But capital punishment isn't dying
Not by a long shot. In just the last six years, 17 states have executed 260 inmates. Three states -- Texas, Florida and Georgia -- account for more than half of those.
The most common method? Lethal injection
Lethal injection is the primary means of execution in all 31 death penalty states. In 1982, Texas became the first state to execute an offender via lethal injection. Since then, the United States has carried out 1,444 executions, and only 171 have relied on another method.
But the drugs are drying up ...
Lethal injection initially required a three-drug cocktail: The first (sodium thiopental or pentobarbital) puts the prisoner to sleep, the second (pancuronium bromide) brings on paralysis, and the final agent (potassium chloride) stops the heart.
In 2010, European drug manufacturers began to ban exports of the cocktail ingredients to the United States. The following year, concerned about the use of sodium thiopental in executions, Illinois-based Hospira stopped making the drug, and Denmark-based Lundbeck banned US prisons from using its pentobarbital.
The United Kingdom also introduced a ban on exporting sodium thiopental, and the European Union took an official stance in 2012 with its Regulation on Products used for Capital Punishment and Torture.
... forcing states to seek new cocktails
Death penalty states began looking for alternatives. Among them: procuring the drugs from alternative sources, devising a one-drug method, employing other drugs such as midazolam or propofol, and using controversial compounding pharmacies to manufacture the drugs.
This has spurred a cascade of lawsuits
Such lawsuits saw a significant uptick in 2014. That's the same year numerous executions, all employing midazolam, were widely considered botched. In Ohio, Dennis McGuire gasped and convulsed for 10 minutes before dying. In Arizona, Joseph Wood snorted and gulped for air as he died over a period of two hours. And in Oklahoma, Clayton Lockett writhed for 43 minutes before succumbing to a heart attack.
After each of those cases, states issued holds on capital punishment while the processes were reviewed. Attorneys for death row inmates in several states have also used these botched efforts to challenge the constitutionality of their clients' executions.
Now, states are looking at alternatives
In 2014, Tennessee said that when lethal injection drugs can't be found, the state can use the electric chair. The next year, Utah successfully passed legislation to reintroduce firing squads. And this month, Arkansas planned to killed 8 men in quick succession before its supply of lethal-injection drug expires. But a federal judge halted the executions, and the state plans to appeal.