In at least seven cases, the families allege there were marks of police torture on the body.
On October 3 last year, in Uttar Pradesh's Baghpat district, Praveen Singh learned that his brother, Sumit Gurjar, had been killed in a shootout with the police.
The FIR or First Information Report lodged by the police said Sumit and an accomplice had robbed a bank and escaped. The police, the FIR said, spotted them the next day and Sumit was killed in a shootout that followed.
Police records show that Sumit Gurjar had several cases of dacoity against him and a bounty of Rs 50,000 on his head.
Praveen has a different version of events. "He was picked up on 30th (September) from Balauni by police. Two of them were wearing uniforms and two were in plainclothes," Sumit Gurjar's brother told NDTV.
Sumit Gurjair had several cases of dacoity against him, police records show.
His family has also alleged torture. "His ribs were broken, his hand was broken, there were also injury marks on his chest," said his father Karam Singh.
These injuries have been recorded in the post-mortem report, reviewed by NDTV.
The family has written to the National Humans Rights Commission. They allege that in "retaliation," the police have booked them as well. "Eight cases have been filed against us and the police are harassing us every day. They are asking us to make a compromise and not go ahead with an inquiry," said Praveen.
The government of Chief Minister Yogi Adityanath has launched a drive to clean Uttar Pradesh of its notorious crime. Since March 2017, soon after Yogi Adityanath took charge, the UP police say they have engaged in 1,142 encounters - shootouts with wanted criminals - which have resulted in 34 deaths and more than 265 injuries.
Apart from the families of those killed, opposition parties and social activists have raised questions on whether these shootouts are genuine or staged.
In at least seven cases, the families allege there were marks of police torture on the body.
In the course of an investigation, NDTV examined the evidence in 14 of the 34 encounter killings, to find a pattern that raises doubts over the shootout theory.
In all the FIRs examined, the language used by the police had what seemed like a cut and paste format, along these lines: "The criminal was on a bike or a car with their accomplice. The police tried to stop them, but the crime suspects/criminals opened fire. This led to the police opening fire in self defence."
In nine out of the ten cases that mentioned an accomplice, the accomplice was unidentified and untraceable.
In at least nine cases the families said their relative - son, brother, husband - was taken from home by the police.
On August 3 last year, the police in Azamgarh in eastern UP shot and killed Jaihind Yadav. The police said he was fleeing on a bike and that two cops were injured in the shootout.
But Jaihind Yadav's father says his son was picked up right in front of him. "I was unwell, so he took me for treatment. I could not even stand. We were waiting for medicines when some people came and picked him up. I didn't know who they were. Then later some people came and said that they were from the Special Task Force," said Shivpoojan Yadav.
According to police records, there were 13 cases against Jaihind Yadav including attempt to murder, and a police reward of Rs 15,000.
Yadav was shot at 21 times, with multiple bullet injuries in his leg and one in his chest.
In Saharanpur district, the family of Mansoor, also known as Mooch, killed in an alleged shootout in September last year, make the same allegation.
"The police came here in plainsclothes. There were two of them. I fed them snacks and they took Mansoor with them," Zubeida, Mansoor's mother, said.
The next thing the family knew, she said, was that Mansoor had died in an encounter. They got to know through the media, Zubeida said.
In at least nine cases, the FIR recorded gunshots to the head or chest. Families have questioned the precision of the firing.
In Muzaffarnagar in western Uttar Pradesh, police claim to have killed Shamim Ansari in a shootout on December 30 last year.
His family is deeply skeptical. This is not the kind of encounter which is possible. Will all the bullets be on the head? Both the bullets have been shot in a close range on his head," said Kamruddin Ansari, Shamim's uncle.
The post-mortem report records the head injuries.
Shamim had 27 cases registered against him, which also included attempt to murder. He had a bounty of Rs 1 lakh. The family says that the bounty was announced after the alleged encounter happened. The families of some others killed in these encounters allege that too.
In at least seven cases, the families allege there were marks of police torture on the body. And in at least four cases the families said that the police had filed false charges against family members to thwart demands for an inquiry into the encounter.
As per police records, four police personnel lost their lives during the encounters. In the cases we investigated, in only one case was there a serious injury or fatality on the police side.
According to the law, encounters are meant to be investigated and testimonies of the families of those killed have to be gathered. But in the NDTV investigation, we found that of the 12 families we interviewed, only the testimony of one family, that of Sumit Gurjar's, was recorded for the inquiry.
Top police officials in UP, contacted for their response, refused to comment.