The characteristics of Friday's shooting attack in Tel Aviv that killed two people are different than any other terror attack that has hit Israel during the wave of violence that has plagued the country over the past three months. In this instance, the assailant is an Israeli Arab resident of the Wadi Ara region, with a history that includes security-related crimes and a stint in prison, and according to members of his family - and a court ruling - he had been defined as "strange," and "mentally unstable." He acted calmly and fired indiscriminately in order to kill as many people as possible, and succeeded in escaping with his weapon before security forces arrived at the scene of the tragedy.The assailant's motives are still unclear, but the circumstances of his life can help to better understand them. He faced a traumatic incident when he was an eyewitness to the death of his cousin, who was shot by police who came to the family's home in 2007 in a drugs raid. A year later, he was arrested on suspicion that he had tried to snatch a soldier's weapon and was sentenced in a plea bargain to five years in prison during which he was hospitalized and received psychiatric care.It is possible that a combination of criminal and nationalistic motives were behind the attack. It is also not clear if he was influenced by nationalistic incitement or religious extremism. Past terror attacks investigated by the Shin Bet domestic security agency show that on more than one occasion the decision by a single terrorist or multiple attackers stems from a number of reasons and not from a single motivation. But even if the Tel Aviv shooter is mentally unstable, it is clear that he carried out the attack with a great deal of expertise.It is still not clear if he was aided by an accomplice or acted alone and arrived at the scene of the murder alone - in a car or on a bus. The assailants in other terror attacks of recent months - most of whom were Palestinians from the West Bank or east Jerusalem - whether they stabbed or ran over their victims, did not flee the scene of the attack. This fact indicates that they wished to be killed by security forces.This is not the case with the suspected assailant from Arara. He did not wait for security forces to kill him, but escaped with the hope that he would be able to hide. The attack bears more of a resemblance to the terror operations inspired by ISIS in Brussels, Paris or California, in which a single attacker, a pair of assailants or a group of terrorists engage in a murderous rampage. In any event, there is no doubt that the easy access to videos, programs and instructions on the Internet, detailing how to make an explosive device or effectively kill someone, provide inspiration to anyone who wants to carry out a terror attack.The attack raises some difficult questions on the functioning of the Shin Bet and police. One of the biggest of these questions is whether there was tracking and follow up on the suspect after he was released from prison. It is surprising as well that authorities allowed the suspect's father to keep a firearm in the house, while his son, a former security prisoner with mental problems, is living at home. Those same authorities will also have to explain why they prevented the publication of the suspect's name in the media in the first 24 hours after the attack, but allowed the publication of his picture.