Police in Calgary say there will be no criminal charges in a dog attack that killed an 86-year-old woman.

Betty Williams was attacked by three dogs while gardening on June 5.

Police say that after speaking to witnesses and consulting with Crown prosecutors, the elements needed to support charges of criminal negligence causing death against the dogs’ owners were not met.

Staff Sgt. Travis Baker says in a news release that investigators determined the owners took reasonable precautions in securing the animals on their property by using a locked gate.

Baker says there’s no way to prove the owners had knowledge the dogs would get out, as they had no history of escaping.

He also says the dogs also had not attacked people before.

“Our investigators also spoke to several witnesses in the neighbourhood, and their interactions with the dogs have been positive,” Baker said in the release Tuesday.

“In this incident, the Crown prosecutor’s office agreed with our assessment that the elements in this case were not met, and therefore, we are unable to lay criminal charges.”

Calgary Community Standards earlier charged the two dog owners in the case. Denis Bagaric and Talyn Calkins are scheduled to appear in court Wednesday on 12 city bylaw offences.

The case also drew attention because it took an ambulance close to half an hour to respond. Both the city and Alberta Health Services ordered reviews.