Andy Parker, the father of the news reporter who was shot dead with her cameraman live on air in Virginia on Wednesday, on Sunday vowed again to succeed in his push for gun control legislation, saying: “They messed with the wrong family.”

Alison Parker, 24, and Adam Ward, 27, worked for WDBJ7, a Virginia station. They were shot dead by Vester Flanagan III, an embittered former colleague. Their interviewee, Vicki Gardner, was seriously wounded but survived.

Flanagan, who filmed the shooting and posted footage to social media, shot himself dead hours later.

On CNN on Sunday, Parker said he and his daughter’s boyfriend, Chris Hurst, wanted to lead a concerted push for reform on issues including basic background checks on all gun purchases, and cited offers of support from gun control activists and groups.

“I have been in contact with Mark Kelly, who is Gabby Giffords’ husband, who was very gracious to reach out to me,” he said. “And we’re going to get together in Washington. Senator [Mark] Warner has also, you know, told me: ‘Whatever we can do to help and facilitate that, let me know.’ Mayor [Michael] Bloomberg’s people have reached out.”

Parker added: “You always think there’s a tipping point. We always thought that when Gabby was shot, something would happen; with Sandy Hook, something would happen; with Aurora, something would happen, and it never did.”

Parker’s rhetorical approach echoed that of Senator Bernie Sanders, the independent Vermont senator who had appeared on the programme in the preceding interview to repeat his message against the “same old, same old” procession of politics in Washington.

“I was listening to Bernie Sanders … and I like what he said,” Parker said, after promising to “hold the politicians’ feet to the fire”.

“He said, and it applied to another matter, ‘same old, same old’ doesn’t work, and it applies to this issue. The reason he’s doing so well in the polls and Donald Trump is doing so well is that people are tired of the same old, same old.

“The difference in this situation is [such feeling has] got to apply to sensible gun control legislation. Controlling the loopholes in gun shows, doing those kind of things.”

Sanders has been criticised by other candidates for the Democratic presidential nomination for allegedly being relatively lax on gun control. On Sunday he pointed to a lifetime voting grade from the NRA which he said was a “D-minus”, and advocated legislation on background checks, semi-automatic weapons and gunshow loopholes.

Sanders said: “I do not accept that I have been weak on this issue. In fact, I have been strong on this issue.

“In fact, coming from a rural state which is not strong on gun control, I think I can get beyond the noise, all of these arguments, people shouting at each other, and come up with real, constructive gun control legislation which most significantly gets guns out of the hands of people who should not have them.”

Parker pointed to California for examples of successful gun control legislation, contrasting it to what he said was inaction in his own state.

He also rejected any discussion of the man who killed his daughter, and attempts this week by 2016 candidates including Trump to focus on mental health policy, saying “there’s a linkage there” between such problems and guns.

Donald Trump says the shooting deaths of Alison Parker and Adam Ward were ‘not about the guns’ but about ‘mental instability’. Guardian

Parker said his daughter “was one of you guys, one of the media”.

“I think people recognising who the victim was and what she represented and how kind and sweet and innocent she was, I think this time it’s going to be different,” he added.

“I’ve done as many interviews probably as I can this week and I don’t want to be like Howard Beale from Network and in essence say: ‘We’re mad as hell and we’re not going to take it anymore’ …

“He got overexposed, I don’t want that to happen. I want to come back when we have real news to report.

“I’m counting on you guys in the media to be there and support this and keep this on the front burner, because it has to be. It can’t go away, it can’t be forgotten, and I’m not going to let that happen.”

In conclusion, Parker added: “I’m telling you, they messed with the wrong family.”