He walked outside with a bloody knife and said he killed his own sister — and a doorbell camera recorded the whole confession, police say.

Michael Egwuagu was arrestedon Friday for allegedly stabbing his pregnant sister, Jennifer Chioma Ebichi, to death, according to the warrant from the sheriff's office in Travis County, Texas. Police said they were able to corroborate a witness’ account thanks to footage captured by a doorbell camera.

Earlier that day, Ebichi contacted the witness, Linda Mura, and another family member, her twin brother, to come to the home where the 32-year-old was later found dead. The pregnant woman had warned that her brother, a 25-year-old former football player for the University of Texas at San Antonio, was in the midst of a crisis.

Mura reportedly arrived at the scene in time to catch Egwuagu exiting the house with a bloody knife. The witness told detectives that Egwuagu then confessed to her, saying “I killed Jennifer.” According to detectives, that moment was captured by the doorbell camera.

This isn’t the first time a doorbell camera aided authorities this week.

Shortly after midnight on New Year’s Day, a man was caught on camerakidnapping a 23-year old woman in downtown Las Vegas. In the video, a woman can be seen running up to the door and desperately banging on it, begging for help. Shortly after, a man runs up and attacks her from behind.

Las Vegas police uploaded the footageto its YouTube channel and the video quickly went viral. Police were able to locate the man, Darnell Rodgers, and arrest him. The woman was also found and is safe, according to police.