Authorities in Arizona are asking the public for help as they investigate the deaths of a man and woman on the South Rim of the Grand Canyon earlier this month.

According to KNXV, the bodies of 25-year-old Garret Bonkowski and 22-year-old Jessica Bartz were discovered on Oct. 1. The couple’s car was found parked in a lot a short distance away.

According to a statement from the National Park Service, it is unclear what happened to the visitors after entering the Grand Canyon National Park on Sept. 18. They reportedly lived in the Phoenix area.

At the time of their visit, police say Bonkowski was wearing a baseball cap with the likeness of Pokemon character Charmander displayed on it.

As of the latest reports available, park spokeswoman Kari Cobb said investigators had not determined if foul play was a likely factor in their deaths.

“We know they came from the top of the rim, but how or why they fell off of the rim we don’t know,” she said, according to the St. George News.

Cobb explained that the park had no record of any missing persons reports connected to the couple.

At this point, law enforcement officers are hoping tips from other visitors who happened to see Bonkowski and Bartz during their trip could help fill in the gaps.

Anyone with information relevant to the investigation can contact investigators by phone at 888-653-0009 or email at nps_isb@nps.gov.

[Featured image: Garret Bonkowski and Jessica Bartz, Grand Canyon National Park]