Alyssa works as a journalist for the local newspaper known as The Raccoon Press. She comes across as pushy, argumentative and is a sore loser. Despite this she hides a very caring personality and can be very protective of others.
While investigating a story one of her co-workers, Kurt, was killed and due to the trauma she suppressed the memory. It wasn't until the viral outbreak caused by William Birkin that she remembered. Kurt was investigating bizarre deaths near the abandoned Raccoon City Hospital. The former administrator, Al Lester was murdering people and feeding them to the plant that contained his deceased wife. Alyssa remembered all of this and destroyed the plant, thus avenging (in part) Kurt.
She fought and succeeded in escaping Raccoon City with several other survivors. After which, she wrote a detailed article with photos from the outbreak exposing Umbrella and their experiments to the people of the world. However this is only within the Outbreak-canon, which isn't regarded as apart of the main series' narrative.
Her job as a reporter has gained her the invaluable ability to pick simple locks. Alyssa also casually used to head to the firing range during her free time to practice with handguns, which has given her the same ability as Kevin to take extra aim and dish out higher damage with a handgun than other characters (minus the burst handgun). Her unique ability is a backward dive to help avoid danger.
Her overall health puts her in 5th place, behind Mark, Kevin, David, and George. This makes her the sturdiest female character, and even has more health than Jim.