Now Playing: Video appears to show police cruiser hitting a biker during parade

Now Playing: The so-called Golden State Killer appears in court in a cage

Now Playing: Boy raises nearly $6k selling lemonade to help with brother's medical bills

Now Playing: Rare, terrifying look at a Hawaiian neighborhood being swallowed up by lava

Now Playing: Belgian police say man in suspected terror attack was set to return to prison

Now Playing: Searchers locate body of guardsman who went missing in Maryland floods

Now Playing: At least 12 Memorial Day twisters reported in northeast Colorado: Officials

Now Playing: 'I'm fine': Valerie Jarrett responds after Roseanne Barr's racist tweet

Now Playing: Missouri Gov. Eric Greitens announces resignation

Now Playing: 1 dead, 5 injured in crash involving school bus in Michigan, police say

Now Playing: What is a TASER?

Now Playing: 'Roseanne' canceled after Roseanne Barr's racist tweet about Valerie Jarrett

Now Playing: Starbucks CEO says racial bias training is investment the company's future

Now Playing: 9-year-old's lemonade stand raises over $5K for baby brother's medical bills

Now Playing: Cincinnati mayor: Teen's death shouldn't be sugar coated

Now Playing: Trump tweets about Mueller probe and North Korea

Now Playing: Community greets high schoolers returning for 1st time since mass shooting

Now Playing: 9-year-old raises over $5K for infant brother with rare disease

Now Playing: Mary Kay Letourneau speaks out 20 years after affair with student

Now Playing: Taxi group calls for change after 5th driver suicide in 5 months