Army drill sergeants get prison for ‘prohibited’ trainee relationships

Two Army drill sergeants were sentenced to prison, busted down to the rank of private, and will be discharged after pleading guitly to engaging in sexual relationships with trainees during boot camp at Fort Leonard Wood, Missouri, officials announced. One of the trainees reported the two drill instructors the day before basic training graduation.

Staff Sgt. Michael Serrano, 34, and Sgt. 1st Class Brian Sullivan, 39, were drill sergeants assigned to Company A, 3rd Chemical Brigade, when they had “prohibited” relationships with newly recruited soldiers and then worked together to cover up the crimes.

The two drill sergeants faced separate court-martial proceedings last week and signed separate plea agreements.

A trainee brought a letter to her unit’s staff duty officer, which described how Sullivan had pursued her while Serrano pursued a second trainee in the unit, Army officials said in a release. The letter was shared with the command and the Army Criminal Investigation Division.

Sullivan pleaded guilty to abusive sexual contact and was sentenced to 84 days in prison. He will be reduced in rank to E-1, and will receive an other than honorable discharge from the Army. After his sentence, Sullivan, 39, will have to register as a sex offender according to state and federal laws, officials said.

Serrano pleaded guilty to engaging in prohibited sexual activity with a trainee and was sentenced to 47 days in prison. He received a reprimand and will be reduced in rank to an E-1. He will also receive a general discharge from the Army.

According to the Army officials, the two drill sergeants had agreed “on a fabricated story in which they denied having any relationship with the trainees,” which they relayed to Army investigators. However, their claims were disputed by the trainees and eyewitness accounts.

‘Position of special trust’

When Task & Purpose first reported the charges in December 2025, both soldiers had been charged with sexually assaulting a trainee, abuse of a training leadership position, and three counts of conspiring to commit prohibited activities with a trainee in a position of trust.

The remaining charges were dismissed under the terms of their plea deals.

The abuse of power charges, which both soldiers were intially faced, is relatively new to military justice. In 2019, Congress added specific Uniform Code of Military Justice penalties for drill sergeants, recruiters, and others in a position “of special trust” who engage in prohibited sexual activities with trainees. Previously, similar crimes would’ve been charged as a failure to obey an order.

“The conviction and sentence in this case shows the seriousness in which the Army takes these types of offenses and the commitment to providing a safe and secure environment in which trainees take their first steps forward as members of our force,” Capt. Tyler Eason, lead prosecutor from the Army Office of Special Trial Counsel, said in the release. “Through the investigative work of Army CID and the courage of the victims in this matter, these Drill Sergeants were held responsible for their actions.”

The two soldiers will serve their sentences at the Midwest Joint Regional Correctional Facility at Fort Leavenworth, Kansas.