As I mentioned in an earlier shot, the study of the "science" of phrenology was one of the reasons for making death masks of executed prisoners. Here four such masks are lined up with a model representing a guide to Phrenology.

Of course the most fiendishly ingenious of the criminal masterminds on display here doesn't have a death mask, but can only vaguely be made out in the reflection above the ill-fated Freeland Morrell on the left.

Though that said, I'm not sure that these guys were in fact criminal masterminds so much as people whose lives went off the rails. (McNamarra possibly thought he was a mastermind, but it didn't work out.) I don't have a lot of information on this lot, but this is what I can give you.

From The Brisbane Courier of 8 January 1886 (page 5):
"Freeland Morrell, who was found guilty of the murder of John Anderson, second mate of the American ship Don Nicholas, on 15th November, was executed in Melbourne gaol to-day. He met his fate with great fortitude. He had refused to see a clergyman or anyone else, except two of his shipmates."
Motive, method...? No idea.

From the Riverina Herald of Tuesday 22 November 1898:
"A MURDERER GOES TO HIS DOOM. ARCHER DIES A PENITENT MAN. MAKES FULL CONFESSION OF HIS CRIME.
[BY ELECTRIC TELEGRAPH.]
(From our own Correspondent.)
MELBOURNE, Monday.
This morning, at 10 o'clock, at the Melbourne Gaol, Alfred Archer, sentenced to death for the murder of William Matthews, whose body was found sown up in a bag in Ulupna Greek, near Strathmerton, expiated his crime on the scaffold.
Archer slept soundly from midnight till seven o'olock this morning and when his body was demanded he walked on to the scaffold firmly.
On being asked if he wished to say any-thing he replied, "I wish to thank one and all the officials here and may God bless them and keep them for that Heavenly kingdom in which I am now prepared to meet my God."
The bolt was then drawn and the prisoner was launched into Eternity.
Prior to his death Archer made a confession of his guilt to the Rev. R. Elliott, who attended him to the last.
He died a penitent man, confident in the hope of salvation.
The Rev. Mr Elliott, who is a minister residing at Numurkah, was most assiduous in his attentions to the condemned man for some time prior to his execution, and he succeeded in preparing him for his awful death, which he met with the utmost fortitude.
The night before the execution Archer told Mr Elliott that he felt quite prepared to die. "I am not a coward by any means," he said, "and shall meet the end quite ready. But if I should collapse, it will not be because I am afraid, but because human nature cannot stand the strain."
As Archer walked to the scaffold, he engaged in prayer, and was most anxious to tell the spectators of his end to live for their God.
Before his death Archer wrote three letters, one to his mother in England, one to a friend at Camberwell, and a third to the Rev Mr Elliott."

From The Argus, Saturday, May 16, 1885
"William Barnes was executed at the Melbourne Gaol yesterday for the murder of Joseph Bragge Slack at South Melbourne on the 9th September last. Since his conviction the prisoner had been much depressed, and on Wednesday he showed signs of breaking down. He became subject to fits of stupor, but during the visits of the Rev. H. R. Scott, who attended him assiduously, he listened attentively, and showed signs of repentance.
...
He said gambling and women had been his ruin. ...The crime for which Barnes suffered the last penalty of the law is doubtless familiar to our readers. His victim, Joseph Bragge Slack, an old man, lived by himself and had some jewellery in his keeping which had once belonged to a man named Thompson, who was a fellow prisoner of Barnes, while the latter was serving a sentence in Pentridge. On the 9th September, a few days after Barnes was liberated, Slack was found dead in his bed with his throat cut, and with a razor clasped in his left hand. The verdict of the jury at the inquest was one of suicide, but three months afterwards Barnes, who had returned to Pentridge on a charge of robbery, confessed that he had gone into Slack's house to steal his jewellery, that he was surprised while under the bed waiting his opportunity, and that in a struggle with Slack he killed him, and made it appear that the unfortunate man had died by his own hand. Slack's body was exhumed, when it was found that his neck was broken. Some of his property was traced to the possession of Barnes, and a complete chain of evidence, resulting in his conviction, was established by the police.

The last one is rather stranger one, since, if guilty, you would think he'd take care not to kill any of his family. Still, it was interesting that he tried to pin the blame on his wife. From the Victoria Police Museum:
"In 1902 Albert E McNamara was convicted for arson and found guilty of manslaughter, after he allegedly set fire to his home, killing his young son.
Police alleged McNamara set the house alight as part of an insurance fraud scheme. His wife and other children escaped unharmed, however his young son was killed in the fire. He was executed in 1902 at Melbourne Gaol.
From The Register, Adelaide, 15 April 1902: THE FATE OF ALBERT McNAMARA.
ATTEMPTED SUICIDE.
MELBOURNE, April 14.
Albert Edward McNamara, who was convicted on a charge of arson involving the death of his son, four years of age, was hanged in the Melbourne Gaol this morning. Since his conviction the prisoner made several attempts to gain the clemency of the Crown, and finally addressed a letter to the Sheriff, throwing the responsibility upon his wife. His conduct throughout has been impassive, and he died protesting his innocence.
Yesterday McNamara sent for a solicitor, and made a will, the contents of which have not yet been disclosed. He slept well last night. His spiritual adviser, the Rev. C. M. Barden, Church of England chaplain, found him calm and rational at daybreak. After breakfast however, when he was left alone for a while, his fortitude gave way. Before anything could be done by the warder posted over the cell, the condemned man ran his head against the iron bars of the door and inflicted a severe wound. He fell on the floor unconscious to all appearances.
Dr. Black was summoned, and dressed the wound with lint, but McNamara remained in a state of apparent stupefaction until 10 o'clock, the hour fixed for his execution.