Yesterday Mr Longley revealed his plan to try to stop similar deaths from happening in New Zealand.
"We'll never know if we've stopped someone from having to go through that, but that's our aim," he told the Herald.
"If we can just stop one person ... Just to stop one family having to go through what we've all been through - it's definitely worthwhile."
The Longleys' plan follows the launch of a safety campaign in Emily's honour at the school she was attending in the UK.
Brockenhurst College said the aim of the week-long All-Ways Safe scheme was to teach students how to stay safe in a variety of situations in a bid to prevent a repeat of what happened to Emily.
The campaign would cover a variety of topics including personal safety, relationship safety, road safety and cyber safety.
Police, victim support, firefighters and other agencies will visit students to spread the message "Be safe, not sorry".
"We have a duty to our students to ensure that they remain safe not only on our campus but in the wider world," principal Di Roberts told Bournemouth's Daily Echo newspaper.
"Our All-Ways Safe week gives us the opportunity to ensure that they are aware of a range of safety issues that might affect them and to encourage them to take necessary steps to safeguard themselves and others."
Mr Longley said the scheme was fantastic.
"I think anything like this is really positive and one of the things that has dawned on us throughout Emily's case and subsequently is that there's a lack of education, particularly on domestic violence.
'Something like that would be the ultimate aim but we're starting smaller. I don't want to go into too much because it's still in the very early stages, but it's our plan to at least talk to school-age kids and relay Emily's story to them and try to raise awareness around domestic violence.
"I think that was the case with Emily. It was so far removed from her reality that I don't think for a minute she thought her life was in danger."
Mr Longley said Emily's death was still very hard to accept.
"We're getting on with our day-to-day lives okay, but we're still deeply mourning the loss of Emily.
"It's a long process that doesn't seem to be getting any easier as time goes by."
Where to get help
* If you are in immediate danger, call 111.
* Shine confidential domestic abuse helpline: 0508 744 633 or 2shine.org.nz.
* Women's Refuge Crisisline: 0800 REFUGE or 0800 733 843 or womensrefuge.org.nz.
* It's Not OK domestic abuse helpline 0800 456 450.
* You can also contact your local police or Citizens' Advice Bureau for advice.