The NSW Supreme Court trial against the 72-year-old reached its final stage on Monday after Justice Dina Yehia sent the jury away to consider its verdicts.
Bowie faces one charge of murder and an alternative count of manslaughter, accused of killing his then 31-year-old wife on or about June 5, 1982 in Walgett or elsewhere in NSW.
After vanishing from her home in northern NSW four decades ago, Mrs Bowie's body has never been found and she has not contacted anyone or been seen since.
Bowie has pleaded not guilty to killing his wife.
In a circumstantial case, prosecutors allege Bowie forced Roxlyn to pen two letters saying she had left her husband and children and then killed her afterwards. The jury heard she was a loving mother and that it was implausible she had simply left her family.
The Crown claims the motivation for the murder was a desire to have an unfettered relationship with another woman living in Sydney.
Evidence was also shown to the jury suggesting Bowie had a tendency of violence towards his domestic partners.
One witness who gave evidence at trial claims they saw someone with Bowie's description burying a bra and pantyhose in a gully at a golf course in Walgett.
Excavations of a property near the Bowie family home also uncovered a dress ring which the Crown claims was owned by Roxlyn.
Prosecutors allege Bowie made a number of admissions to the murder, including telling one woman he had "killed someone before" and separately saying pigs left no trace of a body.
Bowie's legal counsel rejected the prosecution case, saying there was no forensic evidence of a murder or even a struggle occurring at the couple's Walgett home.
The jury heard because Bowie was a violent man who drank heavily and womanised, his wife had ample reason to leave him voluntarily.
Winston Terracini SC said there were flaws in the police investigation and argued that the lengthy delay in bringing the criminal proceedings has caused some disadvantage.
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