“Source?”
Daily Mail. The Uk publication that tells us more about the US than our own homegrown media.
https://www.dailymail.co.uk/news/article-10008971/Police-slammed-letting-person-slip-away-likely-remains-Gabby-Petito-found.html?ito=windows-widget-push-notification&ci=l1E3ZiIB3g
I just looked at their site, see nothing about parents’ supposed arrest. Maybe they removed article.