The identities of those subpoenaed are being kept confidential until the subpoenas are served.
ABC News can report that among those being subpoenaed are former Christie deputy chief of staff Bridget Kelly, former Christie campaign manager Bill Stepien and current Christie press secretary Michael Drewniak. Information is from sources familiar with the legislative probe.
The subpoenas should not surprise any of the three people. Kelly was fired by Christie last week after her role was revealed. Stepien was knocked out of his perch as Christie's top political operative. Drewniak has privately told people he expects to get subpoenaed after 2,000 pages of documents were released Friday, including correspondence to and from him connected to the effort to contain PR damage from the so-called BridgeGate scandal.
Meantime, the state Senate authorized a parallel probe Thursday.
Christie met with homeowners affected by Superstorm Sandy as he tried to put the scandal behind him on Thursday.
The Republican governor and likely 2016 presidential candidate has not been implicated in the lane closures near the George Washington Bridge. The closures were apparently ordered as political payback and caused massive traffic backups.
Four of Christie's key aides have lost their jobs over the plot.
The administration and the Assembly have each hired outside lawyers.
Christie sought Thursday to turn the cameras away from the scandal with a visit - postponed after the bridge scandal hit - to a town on the New Jersey shore hard-hit in October 2012 by Superstorm Sandy.
The governor's work leading New Jersey through the recovery from the storm, which damaged more than 360,000 homes and businesses, helped cement his national reputation as a no-nonsense, hard-driving governor willing to work closely with Democrats to get things done. It also raised his stock as a potential 2016 presidential candidate.
About 100 residents lined up in Manahawkin to see Christie at his first public appearance outside the Statehouse since the scandal broke wide open last week. The setting was the sort of place Christie often appeared in the aftermath of Sandy: a shore fire station. This time, he spoke in front of an antique ladder truck.
He received applause and a few whoops before going on to promise: "I am focused as completely this morning as I was when I woke up on the morning of Oct. 30, 2012, and nothing will distract me from getting the job done. Nothing."