Nick Reiner was arrested on two counts of first-degree murder after his parents, Rob Reiner and Michele Reiner, were found in their Brentwood home. According to sources from TMZ, before Nick was arrested, he was spotted at a Sinclair gas station in Brentwood. According to the employees, the Reiners were regulars at the station for many years.The gas station employees also claimed that they had known Nick Reiner for over 15 years, and they noticed something was off a few days before his parents were brutally murdered. According to the employees, Nick looked "drained" and "abnormal." He was not his usual self.TMZ spoke to multiple employees at the Sinclair gas station, and one of them shared that they saw Reiner two weeks before he was arrested. According to the gas station worker, he looked "tired" and "standoffish."The employees also saw him purchasing a pack of Marlboro Lights, which was a routine thing for him. They also reported that Nick did not look like he was under the influence of drugs or any other substance. However, they noted that his behavior was very different from the Nick that came to the station two months ago. Back then, he was social and even exchanged a few words with the employees.Additionally, a CCTV footage obtained by The Daily Post showed Nick Reiner walking through the gas station during the early hours of the morning, on the same day his parents were murdered.What happened between Nick Reiner and his parents before they were fatally stabbed?In another TMZ post, the outlet revealed that Nick Reiner had been in a verbal fight with his father at a Christmas party hosted by Conan O'Brien.As mentioned above, Nick was acting out of character when he was spotted by the Sinclair gas station employees. TMZ also reported that Nick Reiner looked out of place at Conan O'Brien's Christmas party. Sources revealed that he attended the party in his hoodie when the dress code was formal wear. He kept to himself the whole time and did not make conversation with anyone.However, he did get into an argument with Rob Reiner that was loud enough for people close to them to overhear. The sources also revealed that Rob and Michele left the party right after the argument, but it was unclear as to what time Nick left.In another TMZ report, one source claimed that Nick interrupted Bill Hader while he was in the middle of a conversation with other people. Hader told the filmmaker's son that it was a private conversation before the latter gave him a "thousand-yard stare" and "stormed off."Nick Reiner was arrested for the murder of his parents. People interviewed by TMZ also claimed that they noticed strange changes in his behavior days before their deaths. Gas station employees said he looked tired, withdrawn, and unlike his usual self. Reports from Conan O'Brien's party guests also suggest rising tension between Nick and his father shortly before the tragic incident.Also read: Why has Nick Reiner been placed on suicide watch after his arrest? Everything we know so far