WASHINGTON, D.C. ? An FBI computer consultant gained access to the secret passwords of Director Robert Mueller and others using free software found on the Internet, the latest embarrassment in the bureau’s long struggle to modernize its computers.

The consultant, Joseph Thomas Colon of Springfield, Ill., has pleaded guilty to four misdemeanor counts of intentionally exceeding his authorized computer access, and prosecutors are recommending roughly a year in prison.

Colon’s lawyer is asking U.S. District Judge Richard Leon for probation, contending that an employee in the FBI’s Springfield office gave Colon a password to get into the secret system to speed the installation of a new computer system. The work was part of the ill-fated Trilogy project that Mueller abandoned last year.

Colon, 28, will be sentenced next week.