Perez Molina, a former head of military intelligence during the civil war between 1960 and 1996, has capitalised on the violence with his "strong fist" message against crime and corruption.
"Our proposal is to gradually increase the number of police," Perez Molina said on Friday before campaigning officially ended.
"But until that happens, we are going to have to use the army to patrol the streets." Drug traffickers
He supports the death penalty and has said the government should selectively declare a state of emergency in areas overrun by drug traffickers and tattooed street gang members, blamed for a wave of killings.
|Colom's campaign has focused on |
police and judicial reform [EPA]
Much of the violence ahead of the elections is believed to have been carried out by drug gangs trying to force their congressional and local candidates into office.
In the eastern part of the country, several suspected drug dealers are running for public office in an effort to gain control over key trafficking routes.
Colom has said a vote for Perez Molina would be a step backward into the dark days of Guatemala's civil war that killed almost 250,000 people.
A UN-backed report has blamed the army for 85 per cent of civil war killings.
"Guatemala was ruled with a 'strong fist' for 50 years," Colom said, referring to the country's military rulers.
"Guatemalans have to decide if we are to return to abuse and perversion of the law, or if we want to rely on the law to govern."
Colom's campaign has focused primarily on the need to clean up the police force and the judiciary.
Perez Molina and Colom are both well ahead of the other 12 candidates, including Rigoberta Menchu, a Nobel peace prize laureate and Mayan activist.
Menchu is the first Mayan woman ever to run for president in Guatemala where 42 per cent of the population is descended from the ancient civilisation. She has been polling around 3 per cent.