The state House and Senate are headed toward a showdown over how to overhaul the criminal justice system.

The Senate rolled out it's version of a plan that would end mandatory minimum sentences for most nonviolent drug offenders, increase the jurisdiction of the juvenile courts to 19, make it easier for youthful offenders to expunge their records and drastically raise the minimum value of larceny crimes from $250 to $1,500.

"It's a mixed bag. What I do believe it we want to lighten up on the low-level drug dealers, many of whom are users, and don't want to lighten up on the heavyweight traffickers," Senate Judiciary Chairman William Brownsberger said.

The Senate's bill, backed by most of the Democrat-controlled chamber, would modernize the state's justice system, raise the age of adult crimes from 18 to 19 and changes to the statutory rape law.

Middlesex District Attorney Marian Ryan, the top prosecutor of the state's largest county, supports much of the Senate's bill.

"I am hopeful that as we continue this process, we work further on the Senate bill, we work further with our House colleagues. That that is where we are going to be going. We will make Massachusetts just a little bit more just, a little bit more hopeful and a little bit more compassionate," Ryan said.

Ryan joined dozens of Senators and advocates for reform at at a State House rally Thursday. The crowd of lawmakers and activists agreed that it's time to get rid of decades-old rules that put non-violent drug offenders in jail for years.

"We feel this is an issue that has been developed through the activism of a whole lot of people and I think it's important to hear those voices," Brownsberger said of the lengthy rally at the State House's Grand Staircase.

Before any bill get to Gov. Charlie Baker's desk, the most important voice in the State House belongs to House Speaker Robert DeLeo. The more conservative House is working on their own competing plan that could stop short of all of the provisions the Senate wants. 

DeLeo gave reporters Wednesday little in terms of details of what the House's version of the bill will contain.

"In terms of any specifics, I don’t want to get into that yet because things have not been put into stone at this point," DeLeo said.

Without a compromise early next year, the overhaul could fail to move forward. Still, leaders in both chambers say they expect to begin negotiations on a compromise bill by lawmakers' winter break November 15. Brownsberger expects the Senate to finalize a bill next week and set a debate for the week of October 22.