BOSTON — Responsible for monitoring nearly 90,000 individuals, the Bay State’s probation chief recently warned against overly strict supervision, saying he wants to focus on cases with the highest risk of failure.

“The system’s sort of like a machine — it pulls you in, and we monitor your behavior, and we document every time you’re late,” Probation Commissioner Ed Dolan said during a recent panel discussion. “There’s a danger of sort of over-criminalizing people.”

Probation officers keep tabs on defendants ahead of their trial and after conviction at the order of a judge — sometimes tracking their location around the clock.

Begun in 2001 and expanded since then, the electronic monitoring of probationers now includes 2,391 offenders whose locations are tracked via satellite and 479 who wear bracelets reporting whether they are at home. Dolan said there is too much electronic monitoring.

“In many cases, we’re over-conditioning people, over-supervising,” Dolan said at the panel organized by the think tank MassINC. “I have 3,000 people on GPS today. I really don’t think 3,000 people need to be on GPS today. I think we’re sort of over-using that resource in a lot of ways.”