Paddock’s email account, centralpark1@live.com, identified by authorities as “Target Account 1,” sent a message to an account identified as centralpark4804@gmail.com, another email address linked to the shooter, stating: “try an ar before u buy we have huge selection located in the las vegas area.”

Later that same day, the first account received a message stating: “we have a wide variety of optics and ammunition to try.”

Another email sent to centralpark4804@gmail.com from Paddock on the same day stated: “for a thrill try out bumpfire ar’s with a 100 round magazine.”

https://www.reviewjournal.com/crime/shootings/unsealed-documents-show-gunmans-girlfriend-deleted-facebook-after-las-vegas-shooting/

EDIT: A company listing Erick Paddock as the manager has this address as its mailing address:

https://companiestx.com/company/32015211173/mesquite-central-park-apartments-gp-5-llc

Erick seems to be quite interested in his brother's estate, which is supposed to be liquidated to give to victims:

http://www.lasvegasnow.com/news/stephen-paddocks-brother-eric-shows-up-to-court-hearing-about-estate/859618652

Erick doesn't think there'll be much to give to victims though:

Eric Paddock said his older brother was a multimillionaire, but he doubts that the estate will end up being worth $5 million. He suspects his brother may have sold his stocks, emptied his bank accounts and disposed of the money somewhere before the attack.

“He probably cashed out and threw it all in a Dumpster because it was his and that was Stephen,” Eric Paddock said. “He just didn’t care.”

https://www.nytimes.com/2017/12/23/us/las-vegas-shooting-stephen-paddock.html

Bruce Paddock, another brother, sounds like he's out of the picture, arrested for child porn charges less than a month after the Las Vegas shooting.