Pedro Dias is suspected of having shot and killed two people, a GNR officer and a civilian, in Aguiar da Beira, northern Portugal, last month, on 11 October.
The 44-year-old has been evading authorities ever since despite major manhunts being launched in the region.
Two other people, also a civilian and a police officer, were injured in what is said to have been a botched robbery.
Dias gave himself up to PJ police on Tuesday night after negotiating live coverage of the moment with national channel RTP to “ensure his safety and integrity”.
The fugitive accused authorities of wanting to kill him, media reports claim.
Dias denied the killings and said he will prove his innocence.
In an exclusive interview with RTP he has said he handed himself in because he “couldn’t be a fugitive forever.”
He also told the national broadcaster that he has never left the country and had thought about giving himself up from the
beginning.
He is understood to have been hiding out in the home of a family friend, a retired history teacher, for the past two weeks.
Pedro Dias was driven to the PJ’s Guarda headquarters at around midnight on Tuesday night, and was later taken to the local jail during the early hours of Wednesday morning, at 3am.
A statement from the PJ police explained closed collaboration with the GNR police over the past for weeks has allowed authorities to reconstruct a substantial part of Dias’ movements and collect evidence relative to the “vast criminal activity attributed to him”.
A 61-year-old woman has also been made and questioned as a defendant following “serious suspicions of personal favouritism” at the time of Dias’ arrest and at different times throughout the ordeal.
A massive manhunt was launched in Aguiar da Beira, in northern Portugal, last month for the man believed to be responsible for the spate of shootings that resulted in the death of a GNR police officer and a civilian.
The bloodbath happened after two officers were called to an attempted robbery at a hotel at around 7.25am on the morning of Tuesday 11 October.
While it is not clear whether the main suspect acted alone or whether more assailants were involved, it is believed the bloody shooting spree was triggered after the assailant or assailants were asked by the officers to pull over in a van and provide ID.
The main suspect, shortly afterwards named and identified in the press as 44-year-old Pedro Dias, is believed to have then shot dead one of the officers and shot and injured the other before embarking on a bloody spree, with them both in his van.
In the following hours, two unsuspecting civilians, a couple in a car, were also shot during the rampage, one of whom, the man, died from his injuries. The other, a woman, was left in a critical condition and placed on life support in hospital.
The civilians are said to have been on their way to a fertility treatment appointment in Coimbra, and became the tragic victims of a botched carjacking by the suspect.
A third GNR officer was also shot and injured later on that day.
Hundreds of police officers spent the ensuing days searching for the suspected assailant or assailants in São Pedro do Sul and Arouca, ordering residents of local villages to remain indoors.
While searches on the ground in São Pedro do Sul were later scaled back to a more discreet level, police patrolling of the area was very much active.
Officers were reportedly given orders to shoot to kill should the suspect be sighted.
This, national media reports claim, is what might have led Dias to believe he would be killed.
His surrender and conditions thereof were reportedly communicated to the negotiating parties via a letter passed on through family members.
Dias’ intentions were then transmitted via his lawyer to the head of the PJ police – national PJ director Almeida Rodrigues who was in Indonesia at the time and took the phone call during the early hours of the morning – who gave the go-ahead for RTP to film the events.
Speaking to newspaper Público, lawyer Mónica Quintela explained that RTP reporter Sandra Felgueiras and a journalist from Diário de Coimbra were contacted as “we were worried there would be problems with the handing in of Pedro Dias, we had to guarantee his absolute safety.”
In an exclusive interview with Felgueiras for RTP3, filmed moments before his arrest, Dias claimed his innocence and said he had been “hunted like an animal.”
He refuted any involvement in the murder and added “the GNR officer will certainly have more to say.”
The suspect claimed during his time on the run he survived on €60, sleeping in abandoned houses and swam across the Douro River.
He told Sandra Felgueiras he had tried several times before to give himself up but failed to do so as he felt it couldn’t be done “safely.”
In his interview with RTP he further alleged to have received a phone-call from a GNR Sergeant, the day after the incidents in Aguiar da Beira stating he would be killed.
RTP claims the fugitive guaranteed the entire affair is a “misunderstanding” and told them the past few weeks is living proof that we do not live in a Rule of Law, where police are able to assess who is guilty.
Dias was due to be brought before a judge on Wednesday for an initial hearing.