says that her dog Oliver was shot and killed over Easter weekend at her Charlotte, N.C. home.

The actress, 51, shared on Monday via that Oliver, was shot and killed by an Instacart delivery man on Saturday.

In a series of photos and videos of the German shepherd/beagle mix, Harmon, 51, wrote that the driver "got out of his car, delivered the food & THEN shot [their] dog."

"This Easter weekend a man delivering groceries for Instacart shot & killed our precious Oliver, she wrote. "Our ring camera was charging in the house, which he saw & then knew he wasn’t being recorded."

“We were deeply saddened and disturbed to hear about this incident.

We have no tolerance for violence of any kind, and the shopper account was immediately suspended from our platform. We have been in direct contact with the customer and are cooperating with law enforcement on their investigation,"  an Instacart representative said in a statement to PEOPLE.

Harmon explained that authorities let the driver "go, because he claimed 'self-defense,'" adding, "He did not have a scratch or bite on him nor were his pants torn."

"He was shopping under a woman’s identity," wrote Harmon.

"He shot our dog with my daughters & myself at home & just kept saying, 'Yeah, I shot your dog. Yeah I did.'”

"We are completely traumatized & beyond devastated at the loss of our beloved boy & family member. #RIP OLLIE 🐶🐾🕊️🌈."

The alum also shared an Instagram Story with the news. "To the man who took Ollie away from us: your actions are despicable and inexcusable," she wrote. "You've not only robbed us of a beloved member of our family but you've also traumatized us beyond measure."

"The fact that someone could commit such a heartless act is beyond comprehension to me and I'm devastated that I didn't get to say goodbye to him," she concluded.

The actress' daughter, Avery Sehorn, 18, whom she shares with ex-husband , also shared an Instagram Story mourning Ollie.

"Rest in peace sweet Ollie," wrote Avery. "This is not how you were supposed to go."

Never miss a story — sign up for to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

Representatives for Harmon and Charlotte-Mecklenburg Police Department did not immediately respond to PEOPLE's request for more information on Monday.