The guard claimed Alexander headed straight for her bedroom after entering her property and going inside the main house.
Alexander had also been seen several times leading up to the wedding on the outskirts of her property, the guard said. He had reportedly been spotted the day before the wedding and had been told to stay away from the property.
A detective with the Ventura County Sheriff testified that Spears had called her ex-husband "scary" during a chat with her agent Cade Hudson.
Spears revealed she had a panic attack before her wedding ceremony.
In a lengthy Instagram post coupled with photos from the special night, the Toxic singer admitted she felt "nervous" and had a "panic attack" shortly before she walked down the aisle.
She started the post with "Wow! Holy holy c***! WE DID IT! WE GOT MARRIED! Gggggeeeeezzzzz! It was the most spectacular day!" Going on to say, "I was so nervous all morning but then at 2:00 pm it really hit me … WE'RE GETTING MARRIED! I had a panic attack and then got it together,"
She continued to thank her "crew" who turned her home into "literally a dream castle" before thanking a few of her A-list guests for attending.
"So many incredible people came to our wedding and I'm still in shock! Drew Barrymore my girl crush and Selena Gomez who btw is way prettier in person if that's possible both came! I was speechless. I kissed Madonna again and we danced into the night with Paris Hilton."
She then thanked Versace designer Donatella Versace for designing her dress, adding "I felt so beautiful" and then shared some of the antics from the night: "We all fell on the dancefloor at least 2 times! I mean come on, we were all voguing!"
She ended the post with a sweet tribute to her new husband: "Sam Asghari I love you!"
The pop star didn't make any mention of her ex-husband crashing the event.