Some of these seem tenuous connections. Attributing the contract killing specifically to The Killers, for example, seems unjustified since there are many crime films that feature contract killing.

But Angels with Dirty Faces is a definite reference. That film follows two boyhood friends as they grow up. One becomes a gangster while the other goes straight as a priest.

10 'My beloved is white and ruddy, 
pre-eminent above ten thousand. 
11 His head is as the most fine gold, 
his locks are curled, and black as a raven. 
12 His eyes are like doves beside the water-brooks;
washed with milk, and fitly set. 
13 His cheeks are as a bed of spices,
as banks of sweet herbs; 
his lips are as lilies, dropping with flowing myrrh. 
14 His hands are as rods of gold set with beryl; 
his body is as polished ivory 
overlaid with sapphires. 
15 His legs are as pillars of marble, 
set upon sockets of fine gold; 
his aspect is like Lebanon, excellent as the cedars. 
16 His mouth is most sweet; 
yea, he is altogether lovely. 
This is my beloved, and this is my friend, 
O daughters of Jerusalem.'

How beautiful are your feet
In sandals, O prince's daughter
Your navel is a bowl
Well-rounded with no lack of wine
Your belly, a heap of wheat
Surrounded with lilies
Your breasts,
Clusters of grapes
Your breath, 
Sweet-scented as apples
Nobody's gonna love you the way I loved you.

                                                     (PDF copy)

2 How beautiful are thy steps
in sandals, O prince's daughter! 
The roundings of thy thighs are like
the links of a chain, 
the work of the hands of a skilled workman. 
3 Thy navel is like a round goblet,
wherein no mingled wine is wanting; 
thy belly is like a heap of wheat
set about with lilies. 
4 Thy two breasts are like two fawns 
that are twins of a gazelle. 
5 Thy neck is as a tower of ivory; 

8 This thy stature is like to a palm-tree,
and thy breasts to clusters of grapes. 
9 I said: 'I will climb up into the palm-tree, 
I will take hold of the branches thereof; 
and let thy breasts be as clusters of the vine,
and the smell of thy countenance like apples; 

A novel by Jack London, published in 1909. Martin Eden, a labourer who was once a sailor, has a questioning mind and has undertaken a programme of self-education. He aspires to a higher sort of life, such as that personified by Ruth Moore, a college graduate and the daughter of a wealthy family. He works hard to succeed as a writer, and his work reflects the influence of Herbert Spencer's ethical theories. Although his friend Russ Brissenden, a socialist poet, believes in his work, he has no success. When a newspaper calls him a socialist Ruth deserts him. Then one of his books brings him both fame and money. Ruth seeks him out, but he realizes her true nature and turns away from her. He becomes depressed, and Russ's suicide makes matters worse. He grows to despise the society that has finally honoured him, and he commits suicide on a sea voyage.

The Wordsworth Companion to Literature in English (Wordsworth Editions 1994) p. 599.

Jack London's Martin Eden caught my eye, and I turned mechanically to the last sentence, as if my fingers knew what they would find there. Martin Eden, at the height of his fame, kills himself by slipping out through the porthole of his steamer cabin into the Pacific, and as he feels the water slowly filling his lungs, he gains, in a final glimmer of lucidity, some understanding, maybe of the meaning of life, but "at the instant he knew, he ceased to know."

Umberto Eco, The Mysterious Flame of Queen Loana (Secker and Warburg 2005), p. 129.