On the second anniversary of the Sandy Hook shootings, in Newtown, Connecticut, in which 20 children and seven adults were shot and killed by gunman Adam Lanza, a poll shows that the majority of Americans support their second amendment-protected right to bear arms over tighter restriction of access to firearms.

The research by the Pew Research Centre this month found that 52% of respondents said it was more important to protect existing gun ownership rights, while 46% said that they thought it was more important to control access to firearms.

The centre said that it was the first time in two decades that a survey had found the majority of Americans in favour of gun rights over gun control, with a 2000 survey showing 29% saying gun rights were more important, and a survey one month after the killings in Newtown, Connecticut, finding that 45% favoured gun rights.

"To some extent, this is the continuation of a trend," Jocelyn Kiley, associate director for research at the Pew Research Center – a politically neutral thinktank – told the New York Times. "It may be that Newtown stunted that trend to some extent."

The killings at Sandy Hook Elementary School led to widespread calls for access to firearms to be restricted, and tighter background checks to be introduced for those buying them.

As part of the poll, 57% also said that they believed that gun ownership helped to protect people from crime, while 38% said it would be more likely to endanger them.

However, other polls show that Americans favour specific gun control policies. When surveyed by Quinnipiac in July, 97% of respondents said they favoured the introduction of background checks on people purchasing firearms.

The US Senate has yet to pass legislation restricting gun ownership rights in the wake of Sandy Hook.