Surprising details of the police culture emerged during the trial of former constable Danijel Radosavljevic, who indecently assaulted female police officers between 2010 and 2011.

Radosavljevic was found guilty in Wollongong Local Court on Thursday of four indecent assaults, one common assault and one count of committing an act of indecency.

Radosavljevic, now of Sydney, exposed his penis and masturbated in front of one female officer.

He also slapped and pinched women on the bottom and massaged another's shoulders.

The court heard it was common for Radosavljevic to discuss his need to masturbate, expose himself, and send women explicit text and picture messages, including a video of himself masturbating.

Radosavljevic resigned from the force in 2012 after the allegations surfaced.

Five women gave evidence against Radosavljevic during a January hearing.

Four of the complainants were police officers and one was a civilian.

The court heard Radosavljevic's misconduct began in 2010 when he sent one of the women a text message that said: "I bet you have a hot arse under those pants."

He then went on to send her messages with explicit pictures that included a man's groin wearing blue speedos, a penis and a man with an erection wearing blue police cargo pants.

The latter included a message saying: "This is what you do to me."

The court heard the woman avoided Radosavljevic and told him she did not wish to receive any more messages from him.

By July 2011 the woman had made up a boyfriend in an attempt to deter Radosavljevic, but he exposed his penis to her and then insisted she watch him masturbate.

The next day he sent her a text message thanking her for the night before and saying: "Sorry you felt uncomfortable, I didn't mean for that to happen, I won't put you in that position again."

The court heard Radosavljevic slapped and pinched other complainants on the backside, sometimes in front of witnesses.

It heard Radosavljevic massaged one woman's shoulders, who shrugged him off and told him not to touch her.

During the trial, defence barrister Bryan Robinson claimed the charges had stemmed from a culture of horseplay, which included pranks and privileges.

One witness admitted receiving a lift home from Radosavljevic, while he had been on duty and drunk.

Other pranks included placing fingerprint ink on door knobs or telephone handsets, changing computer backgrounds or phone languages if left unattended, wrestling and using sticky tape across pigeon holes or hallways.

Radosavljevic admitted on the witness stand he had often grabbed the magazine of other officers' guns as a test of gun retention.

Mr Robinson argued the pictures of his client's penis – which the offender claimed had been taken for his wife – had been sent as a prank after he left his phone unattended.

The defence claimed the shoulder massage had actually been a shake to wake up a sleeping person and the bottom pinch had actually been a flick intended to move a person blocking his way.

But magistrate Susan McGowan rejected the explanations and found Radosavljevic guilty.

Although the magistrate did find that the massage did not constitute an indecent assault, she instead convicted Radosavljevic of the back-up charge of common assault.

Ms McGowan ordered a sentencing options report to be prepared and reserved her judgment until June 19.