Sgt. Sean Murphy said he leaked the photos taken during Dzhokhar Tsarnaev's capture to counter what he called a glamorized image of Tsarnaev on the cover of Rolling Stone magazine.
Three of Murphy's photos show a bloody and battered Tsarnaev, emerging from a boat in a backyard, blood spattered across his face and the red dot of a sniper's laser sight trained on his head.
Murphy was not authorized to release the photos. He has already served a one-day, unpaid suspension.
After a status hearing at state police headquarters on Tuesday, he was put on desk duty while an investigation continues.
Murphy released the photos to Boston Magazine and said the Rolling Stones cover was an insult to police, military members and the families of anyone killed in the line of duty.
"This guy is evil," Murphy said. "This is the real Boston bomber. Not someone fluffed and buffed for the cover of Rolling Stone magazine."
Rolling Stone said the cover story on Tsarnaev was part of its "long-standing commitment to serious and thoughtful coverage of the most important political and cultural issues of our day."
Tsarnaev, 20, has pleaded not guilty in connection with the April 15 bombing that killed three and injured or maimed 260. He's also accused of killing a Massachusetts Institute of Technology police officer while on the run three days later. Tsarnaev escaped from police following a shootout in the Boston suburb of Watertown that day, during which he ran over his brother and alleged co-conspirator, Tamerlan Tsarnaev. His brother died of injuries suffered during the confrontation.
The Associated Press contributed to this report.