NAIROBI, Kenya (AP) — A Kenyan court on Wednesday found two men guilty for supporting the days-long 2013 attack on Nairobi’s upscale Westgate Mall that left 67 people dead.

Chief Magistrate Francis Andayi acquitted a third suspect.

The attack by four gunmen with the Somalia-based extremist group al-Shabab was the first large-scale assault in Kenya's capital. Al-Shabab had vowed retribution on Kenya for sending troops in 2011 to fight the group in Somalia.

The magistrate said although there is no specific evidence that the two men gave material support to the attackers, constant communication with the gunmen “was giving support to their endeavors.”

“The pattern of their communication betrays the fact that they may have been just friends with the attackers,” Andayi said while reading the judgment that took three hours.

According to a police reconstruction, the gunmen split into two groups. One went through the mall’s main entrance and another went through the vehicle entrance, tossing grenades and spraying bullets.

Kenya's police and army were widely criticized for their response to the attack. It took at least two hours before the police tactical team went into the mall, leaving security guards and volunteers to fend for those inside.

Lack of coordination between the military and the police led to friendly fire in which one police officer was killed. The attackers died of smoke inhalation after the army allegedly blew up a part of the mall where they were hiding.

For survivors of the attack like security guard David Odhiambo, the two men convicted Wednesday should be hanged. He was shot in the head, injuries that led him to be fired.

“They should be killed,” he said from a Nairobi hospital where he went for tests this week. He said hardly a month goes by without him visiting the hospital for one problem or another.

Some analysts say lessons still unlearned by Kenya in the attack will continue to provide opportunities for al-Shabab to exploit.

“The many command and overt operational failures of (the government) on that Saturday caused a ‘siege’ to develop that lasted nearly four days," said former U.S. Marine and security analyst Andrew Franklin.

That “was followed up by official silence that has lasted to date," with no formal report made publicly available, he said.