A Hamilton police officer who is already serving a demotion for having sex with a sex worker has been demoted again — this time for picking up a drunk woman on duty and having sex with her.

Const. Thomas McKay pleaded guilty to police act charges of discreditable conduct during a police act hearing Tuesday.

"I'm incredibly embarrassed and sorry to be here," McKay said during the hearing.

According to an agreed statement of facts in the case, the incident happened in July of last year, when McKay was working a paid duty shift in Hess Village.

While on duty and in uniform near the end of his shift, McKay ran into a woman he didn't know who had been drinking. He talked with her for about 15 minutes.

Then at the end of his shift around 3:15 a.m., McKay approached the woman again alongside a second officer and offered her a ride home — even though she wasn't in distress and didn't ask for a ride, the statement reads.

The woman accepted the offer, and all three people got in McKay's personal vehicle. The two officers sat in the front and she sat in the back.

But instead of driving the woman home, McKay drove back to the east end station. The two officers went into the station while the woman waited in the car.

McKay changed into his street clothes, got back into the car with the woman, and drove her to her home on the Mountain. According to the agreed statement of facts, they then went inside and had consensual sex.

McKay stayed inside for about 45 minutes and then left.

"The Hamilton Police Service cannot be seen to condone this type of behaviour," said police prosecutor Marco Visentini.

"The public certainly doesn't expect a police officer to act that way."

Even before this incident, McKay was already serving another demotion for receiving oral sex from a sex worker and then lying and saying that she was an informant when another officer caught him. Visentini said this "appears to be part of a greater pattern of behaviour of sexual conduct."

His previous demotion was set to run until April 2016. After pleading guilty on these second charges, that demotion has been extended to leave him second class constable until April 2017.

He will forfeit $17,000 in salary because of this second demotion. That's on top of $40,000 on his last demotion.

Visentini told the hearing that should McKay end up before the tribunal again, he would almost certainly be fired. He did note, however, that the officer is entitled to "some mitigation" for pleading guilty and sparing the woman he had sex with from having to testify at a hearing.

McKay's legal counsel Gary Clewly told reporters after the hearing that his client knows this was a "dumb thing to do," but that he's "otherwise a diligent officer."

"[The woman] was not a kid, and she knew what she was doing."