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LANCASTER (CBSDFW.COM) – A prom after-party in Lancaster turned violent after a teenager was shot and another person was assaulted in a party that grew to over 500 people thanks to social media, authorities say.

The teenager that was shot has been released from the hospital, but concerns have grown after it was discovered the suspects in the violence were not part of the Red Oak High School crowd that was originally invited.

Dallas County sheriff’s deputies arrived at the party just after 3:00 a.m.

Authorities believe two or three suspects showed up at the after-party uninvited and proceeded to rob some people. A teenager was then shot and another person was physically assaulted.

Kelvin Martinez who attended the party said he left the party before the violence started.

“We were lucky enough to have good timing and head to IHOP… right when all this was happening,” said Martinez.

Investigators also believe the suspects blended into the crowd as people began to leave the party. Authorities continue to search for the possible suspects.

“The address just got spread around, and I guess the wrong people got it,” said Martinez

Although there were some adult chaperones according to authorities, one neighbor who didn’t want to be identified said there should have been more supervision at the party.

“You can be a good kid and be in the wrong place. I’m sure more than half of those kids who were here last night just wanted to have a good time,” said the neighbor. “They were just in the wrong place.”

Police are not sure if the suspects are teenagers or how they left the party.

“It’s pretty scary. A part of me kind of knew that when you get this many people together – this many teenagers – it’s not professionally organized,” said Martinez, “there’s a chance of something happening.”