5 Useful Things To Know Today: Oct. 20

1. Temperatures cool down to a high of 60 degrees today, but the rain is expected to go away with only a 10 percent chance of precipitation. Expect the day to be mostly cloudy.

2. As we enter Halloween season, be sure to check out . Patch will be featuring the Haunted Forest in a "Did You Know?" column next week.

3. . The Gaithersburg man charged with killing his stepdaughter stabbed and cut her more than 40 times and had married her mother in “an immigration sham type of marriage,” Montgomery County prosecutors said yesterday at his bond review.

4. In case you missed it: Thirteen Maryland hospitals participated alongside local fire and rescue officials in the response to a mock terrorist attack in the D.C. Metropolitan area Wednesday morning. As a part of Capital Shield 2012, the exercise tested the region's ability to respond to a mass casualty terrorist attack.

5. On this day in history: The Senate ratified the Louisiana Purchase in 1803, and the Sydney Opera House was opened by Queen Elizabeth II in 1973.