Actress Learns Her Niece Is Among Bar Shooting Victims

Authorities are still trying to piece together the facts regarding the mass shooting at a bar in Thousand Oaks, California, that left 13 people dead, including the gunman. "We have no idea what the motive is at this point," says the local sheriff. Here is what is known so far, including sad news for Sister Sister actress Tamera Mowry-Housley:

• The shooter: He's been identified as Ian David Long, 28, ABC News reports. Witnesses say he was clad in black and said nothing before opening fire in the Borderline Bar & Grill with a legally purchased Glock .45-caliber handgun. Police think he died of a self-inflicted gunshot inside the bar. The Los Angeles Times also has this odd detail: Police believe the gunman drove his mother's car there.
• Former Marine: Long served in the Marines for five years, including a tour in Afghanistan's Helmand Province, reports NBC News. He left the military in 2013. In April of this year, police responded to his home on a complaint of disturbing the peace and found Long to be "somewhat irate and acting irrationally." However, he was not taken into custody after an evaluation by mental health professionals. A neighbor tells the LAT that he thinks Long had PTSD. "I know he tore the house up." Long lived with his mother.

• The victims: Eleven people were killed inside the bar, and not all of their identities have been released. Sheriff's Sgt. Ron Helus died early Thursday at the hospital after being shot multiple times. He was among the first law-enforcement officers at the scene. "He was willing to sacrifice his life for the sake of others," says Ventura County Sheriff Geoff Dean, per NBC News. "As I told his wife, he died a hero." Helus had planned to retire next year.
• Niece killed: On Thursday morning, Sister Sister actress Tamera Mowry-Housley had been trying to track down her 18-year-old niece, who was at the bar at the time of the shooting. The actress's husband, Adam Housley, wrote on Twitter: "Please pray if you believe....pray." By the afternoon, however, the sad confirmation came: Pepperdine University freshman Alaina Housley had been killed, reports USA Today. "Our hearts are broken," said the couple in a statement. "Alaina was an incredible young woman."
• More victims named: Other victims named so far include Cody Coffman, 22, Justin Meek, 23, Noel Sparks, 21, and Sean Adler (variously reported as Sean Alder). The Ventura County Star and KTLA are keeping lists of victims and their stories.
• The bedlam: "I was on the dance floor dancing and all of a sudden I heard the shots," Teylor Whittler tells ABC News. "I ended up getting caught on the ground and stumbled over by multiple people," and at one point she got hit in the head with a bar stool being hurled at a window by people trying to escape. Witnesses say the shooter also threw at least one smoke bomb.
• Another witness: "I ran out the front door," one man tells CBS News. "I hear chairs being thrown out the window, people were trying to get out the window and the gunman ... he went behind the cash register. ... There was probably 12 shots before I got out the front door."
• Country theme: The Borderline is near California Lutheran University, as well as Pepperdine in Malibu, Moorpark College in Moorpark, and California State University Channel Islands in Camarillo, reports the AP. The site includes a large dance hall, and Wednesday was "College Country Night."

(Read our initial report on the shooting here.)