What type of declaration you are talking about ?
if he is catholic he has to get divorce from ecclesial court, unless he get divorce from ecclesial church court he cannt marry again in Church nor most of the girls families will not agree to give their daughter again. as he already has arranged marriage means his family is traditional one, and church will not recognise his 2nd marriage unless its nullified in ecclesial chrch court. almost same proceedures are followed in other Christian denominations too.
to file in Divorce in court also he has to wait for a year, he can show the court that she deserted him without valid reasons, but file for divorce before she file any criminal cases on him.