Darren Campbell “systematically” shot and killed his wife and two children before setting tennis player James Blake’s home afire and shooting himself, according to police.

Darrin Campbell Committed Murder-Suicide

Though it was suspected from the start that Campbell, 49, was responsible for the deaths of his wife, Kimberly Campbell, 51, and children Colin Campbell, 18, and Megan Campbell, 15, authorities have now confirmed his guilt.

"This has been determined to be a murder-suicide," Hillsborough County sheriff's Col. Donna Lusczynski said, according to The Tampa Bay Times. "[Darrin Campbell] systematically shot his son, his daughter and his wife in the head. He then placed fireworks throughout the residence, used an accelerant to assist in lighting the fire, lit the fire, and then shot himself."

Earlier in the week, it was confirmed that Campbell had purchased half a dozen packages of firecrackers and fireworks from Phantom Fireworks. However, according to the store’s vice president, the fireworks alone couldn’t have caused the massive blaze. The authorities now know that Campbell used an accelerant, which amplified the effects.

At this time, it is unknown why Campbell, a COO of a local digital records company, committed the tragic act.

The Campbell family had been renting the 5-bedroom home in Tampa, Fla., from Blake for roughly two years. Blake had purchased the home in the upscale Avila community in 2005 for $1.5 million.