Politics in Pakistan is a dangerous game. As the country gears up for its first ever democratic transition from one elected government to another, militants have drastically upped the violence. In the last three weeks, there have been around 50 bomb blasts, mainly targeting secular, liberal parties. More than 80 people have been killed, including two contesting candidates, and more than 350 people have been injured. It is no wonder that many are describing this as Pakistan's bloodiest election ever.

Amid this deluge of violence, it can be easy to lose sight of the individuals who have lost their lives. On Friday, Chaudhry Zulfiqar Ali, the main prosecutor in the case of Benazir Bhutto's murder, was shot dead in Islamabad. Ali was driving to a hearing pertaining to the Bhutto case, when two gunmen on motorbikes shot him multiple times in the head and chest. Several hours later, in an apparently unrelated attack in Karachi, Sadiq Zaman Khattak, a candidate for the Awami National party (ANP), was shot dead, along with his six-year-old son. He was the first National Assembly candidate to be killed during this campaign.

Taken together, the two murders demonstrate how political violence – whether one is actually a party politician, or merely sticking one's head above the parapet – has become the norm in Pakistan. The scale of political deaths is dizzying; the ANP alone has lost 700 members to terrorism in the past five years. The death toll of prominent public figures – such as Bhutto, and former Punjab governor Salmaan Taseer – is rising, yet most of the time their killers never face justice.

Ali's death, in particular, illustrates the precariousness of the situation. There is no clarity about who killed him. Certainly, as one of Pakistan's most senior criminal lawyers, he had no shortage of enemies. At the time of his death, he was prosecuting seven men for their alleged role in the Mumbai terror attacks of 2008, which were orchestrated by militant group Lashkar-e-Taiba (LeT).

Yet, as has been widely reported, he was also in the process of leading the charge against the former military dictator Pervez Musharraf, who is accused of failing to provide adequate security for Bhutto before her death. Ali had received death threats. There is a grim irony that his friends say he was never given the extra security detail he was promised. As yet, no militant organisation has claimed responsibility for the attack, and the police have not given an official statement on who is to blame.

In a country where conspiracy theories are the national pastime, it took just hours for it to circulate that Ali had been killed not by militants but by the powerful security agencies. Ever since Musharraf's arrest, many have said that it is inconceivable that the army would allow a former leader to be tried for acts committed while he was head of the military. Most people I've spoken to since Ali's death view it as a veiled threat to those seeking to pursue the case.

Whether or not this turns out to be true – and of course, it is entirely possible that Ali was killed by one of the militant groups he had angered – a very real question exists. If you can have no trust in those supposed to protect you, you are incredibly vulnerable. The military and intelligence officially severed ties with militant groups more than a decade ago, but in practice all elements have not maintained this separation. Groups such as LeT have attacked military targets, yet elements of the Inter-Services Intelligence (ISI) still support them and use them to fight proxy wars in India and Kashmir.

Most of the deaths in this election campaign have been at the hands of militants. Yet when it comes to political deaths, the hands of the security services are far from clean. The ISI has undoubtedly been involved in extrajudicial killings of separatist politicians in Balochistan, for starters. Domestic journalists, remarkably free on most topics, are cautious when it comes to reporting on the ISI or senior military leadership.

This lack of trust in official agencies reflects and feeds back into Pakistan's fundamental barrier to tackling militancy: the fact that the security services do not speak with one voice when it comes to terrorism. We do not know – and probably will never find out – who was responsible for Ali's death. But it demonstrates the delicate balancing act in Pakistan, where it is fatally dangerous to anger either the militants who oppose the democratic process, or the security forces who are supposed to defend it.