The New Brunswick, New Jersey, law firm of Benedict & Altman, which was representing Smith, told the Associated Press Smith planned to plead innocent to the charges.
However, Smith since has changed lawyers. A representative of Benedict & Altman declined to disclose the reason for the change.
A grand jury in Trenton will consider whether to indict Smith on charges of interrupting public communication, conspiracy to commit the offense, attempting to commit the offense, theft of computer service, and wrongful access to computer systems.
If the grand jury indicts Smith, the case will go to a jury trial, said Rita Malley, a spokeswoman for the New Jersey Attorney General's Office.
The Melissa virus began spreading across the Internet March 26, using a combination of Microsoft's Word and Outlook programs to send copies of itself to people in a user's email address book.
Antivirus company Network Associates said the virus was inserted into the wild when a person posted it to an "alt.sex" newsgroup. The infected file was posted from an America Online account called Skyroket, but the owner of that account denied involvement.
However, AOL traced Melissa information to a New Jersey location, and contacted New Jersey law enforcement officials, according to the New Jersey Attorney General's Office.
That trace apparently led to Monmouth Internet Corporation, where Smith had an account. Mark Stevens, operations manager at Monmouth Internet, said the New Jersey State Police gave him a warrant requesting log information about which user had been assigned a temporary Internet address.
"Monmouth Internet does believe in the protection of the privacy of its customers, but does give full cooperation to the authorities in the fulfillment of warrants and subpoenas," Stevens said.
Smith since has canceled his account with the Internet service provider, Stevens said.
Some amateur sleuthing led to a connection between Smith and a virus writer code-named VicodenES. Although the New Jersey Attorney General's Office initially said there appeared to be no connection, they now have backed off from that stance, said spokesman Paul Loriquet.