Franks said he had once met a young lawyer who was being told to bring charges down to a level where a guilty plea could be secured - for example the man was told to lower a charge of rape to one of indecent assault.
Sensible Sentencing's child abuse spokesman Scott Guthrie spoke on the case of 3-year-old Moko Rangitoheriri, whose death prompted outrage around the country.
Moko was killed by caregivers 26-year-old Tania Shailer and 43-year-old David William Haerewa after weeks of horrific abuse. The pair were initially charged with murder, but the charge was lowered to manslaughter to secure a guilty plea.
"Hopefully we can start the journey to allow Moko to rest in peace today," Guthrie told the committee.
"Somewhere, someone has done a deal and the charge was reduced to manslaughter . . . Parliament is the highest court in the land, yet we believe you have been treated with absolute disdain, even, dare I say, contempt.
"All lives of all children before Moko and those who come after him will pave the way for an open, honest, and transparent justice system."
MP Denis O'Rourke said "defective law" was what led to the manslaughter convictions in Moko's case.
He questioned why the charge was not brought as an alternative so a jury could pick between murder or manslaughter for their verdict.
He laid the reasoning down to "very poor drafting in the Criminal Procedures Act".
"It should be possible for the charge to be laid in the alternative. In fact, it isn't," he said.
It was due to "difficulties presented in the drafting of that legislation".
"I believe that this committee needs to look in significant detail at that legislation, because it is actually a barrier to justice."
Franks said he was trying to avoid pinning the plea bargaining issue on one thing. He wanted to see changes allowing victims to be heard in court, not just through victim impact statements, but to have a voice in the process.
He said the "balance" of the system needed to be readdressed.
"It's gone septic."
Sensible Sentencing head Garth McVicar told NZME they had been "waiting for the perfect storm" to bring up the issue of how funding for Crown prosecutors negatively affected their work.
"We've done a big slide backwards as far as the treatment of victims in this country," he said.
"From the victim's perspective it's appalling. I think from the justice perspective it's appalling too. All it does is it disposes of a case quicker, that doesn't mean justice is served."
He said it was "a dollar issue".
The select committee will consider the submissions and decide where to from there.
