He described killing his girlfriend on Reddit. Now he's been arrested in Texas.

Ager Hasan, 24, has allegedly been using Reddit and Instagram to share details of him killing his girlfriend. Ager Hasan, 24, has allegedly been using Reddit and Instagram to share details of him killing his girlfriend. Photo: Waterloo Regional Police Service Photo: Waterloo Regional Police Service Image 1 of / 36 Caption Close He described killing his girlfriend on Reddit. Now he's been arrested in Texas. 1 / 36 Back to Gallery

A Canadian man has been arrested in Texas after he shared details of him killing his girlfriend on Reddit.

Ager Hasan, 24, from Hamilton, Ontario, was apprehended Tuesday in San Antonio during a traffic stop on a second-degree murder warrant issued jointly by the U.S. and Canada.

Hasan's 22-year-old girlfriend, Melinda Vasilije, was found dead in her apartment from multiple stab wounds at 3 a.m. April 28, Waterloo Regional Police said.

Just hours after killing her, Hasan crossed over into the U.S., police said. He was captured on security video putting Pennsylvania plates on his vehicle that he took from another vehicle in a Walmart parking lot.

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Four days later, Hasan allegedly took to Reddit to recount his relationship and what led to him killing his girlfriend, said Cherri Greeno, media relations coordinator for Waterloo Regional Police Service.

"I go up to her to try and give her a hug, almost out no where she grabs a knife by the sink," Hasan allegedly wrote under his Reddit username Redasblue101 in a now-deleted post. "Initially I thought was just going to hold it to try and tell me to leave. She doesn't. She comes at me in full force, aiming towards my face. I tell her to stop. She doesn't, I tried grabbing the knife but ended up cutting my hands. After a few cuts I lost it. I freaked out, I was scared and in a state of shock. Never in a hundred years did I think she would use a knife against me. Out of shock and fear I grab one. I hit her with it, almost blindly. A few times. I didn't know what happened."

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Hasan goes on to write about how shocked he was about what happened. He thought she had just passed out. Then he saw "the blood, and started freaking out and just ran."

"She was with me the most, we were each other's best friends, she would tell me everything. Her deepest secrets that not even her friends or family knows. The amount of regret and sadness is beyond words," Hasan wrote.

On Sunday, Hasan also allegedly posted two photos on Instagram. One photo appeared to show him with Vasilije and the other showed a nondescript man sitting in a dark room with the caption, "I'm coming home. It's time to end the dark path I've been traveling and give people the closure they deserve."