Mojave County Sheriff's Deputy Dale Lent and FBI agents processed the spot where the armored car was believed to have been stopped.
On June 16, 1977, 300 miles northwest of where the armored van had been abandoned, a body in a black canvas bag was discovered in Debbie's Cove in Lake Mead by a pair of anglers.
After recovering the body, a wallet was found in the back pocket, and the victim was identified as Cecil Newkirk, one of the two missing courier guards.
A subsequent autopsy indicated that the guard found had been severely beaten and had two large welts consistent with those inflicted by a high voltage taser gun.
The day after the robbery, he had towed the pickup truck of two men who claimed to be fishing and had inadvertently backed into Lake Mead at a boat ramp named Bonelli Landing.
Agents returned to Lake Mead, and after searching between Bonelli Landing and the boat rental shop across the shore, Russell Dempsey's body was recovered along with a garrote made out of two pieces of wood and rope and a second black canvas bag nearby, containing a blanket and tarp.
Further investigation revealed that both brothers were in financial trouble, but after the robbery, their debts had been paid completely, and they had purchased new vehicles, spending money beyond their legal means.
Examinations revealed the same batch of concrete that left the dust stuck in the canvas bag recovered at Lake Mead.
However, the station owner could not positively identify Patrick Poland, but he did confirm that their father's pickup truck was the one he towed from Bonelli Landing.
On July 27, 1977, agents arrived at Michael Poland's house with a search warrant, but he claimed that he was in Las Vegas buying jewels on the day of the heist.
A search of Patrick's house yielded a stash of weapons, $16,000 in cash, another siren, and a belt with a space for a badge.
After much investigation, it was revealed that neither of the cars the brothers owned before the robbery left the tire tracks found near the crime scene.
[6] On May 18, 1978, after nearly a year of investigation, a Federal Grand Jury returned an indictment against the Poland brothers for robbery, kidnapping and murder.
However, FBI agents suspected that both brothers would not surrender quietly, so they decided to arrest them away from their homes, fearing a shootout.
In November 1979, an Arizona state jury returned the guilty verdict for murder, which meant the death penalty for both of them, but they appealed their convictions.
[7] U.S. Attorney Melvin Macdonald, outraged that the Poland brothers would possibly get away with murder, was deputized as an Arizona State Prosecutor.
After much pondering, a crucial piece of evidence was found in the form of Cecil Newkirk's self-winding watch, which stopped working at 10:37 p.m. on May 26, 1977.
The prosecutor explained that the Polands had been there to dump the bodies, which convinced the jury to return the guilty verdicts for the murder of Russell Dempsey and Cecil Newkirk on November 18, 1982.
The defendants appealed again, but this time, the United States Supreme Court affirmed the death sentences for the Polands.
[3] In 1997, Michael Poland's cell on Death Row was searched and found to include an escape plan, handcuff keys, a suicide drug, several knives, and a lock pick.
They put on an emergency lighting system, a siren that could be turned on with a simple switch, and a license plate similar to the one used by the Arizona Highway Patrol and the department's door decals.
They readied their tools needed for the heist, including a uniform similar to the one used by the Arizona Highway Patrol to be worn, and went to an ideal spot to wait.
After pulling the armored car over, Patrick went to the side of the van and approached the guards, and asked the driver to step out.
However, when Patrick left, his brother did not follow, so he reversed the fake cruiser in front of the armored car and proceeded to see what was happening.
Patrick's decision to reverse the car to a spot in front of the van left the tire tracks, which investigators would later find.
[10] He requested, for his last meal: three fried eggs sunny side up; four slices of bacon, an order of hash browns, two slices of whole wheat toast with two pats of real butter, two individual serving size boxes of Raisin Bran cereal, two cartons of milk, and two cups of Tasters Choice coffee.
[13][14] During one of the clemency hearings, the relatives of Cecil Newkirk and Russell Dempsey, the two guards murdered during the robbery, were not forgiving.
Among the witnesses to the execution were the widow of one of the murdered guards, Lola Newkirk, relatives of the deceased, Patrick's girlfriend, Sherri Jo Christensen, and also Melvin McDonald, the Arizona state prosecutor who had initially ensured that the brothers would be sentenced to death, but tried to persuade the Arizona Board of Executive Clemency to commute Patrick's death sentence to life in prison yet failed.